Update esp-hal/README

[JurajSadel]

Thank you!

Thank you for your contribution.
Please make sure that your submission includes the following:

Must

• The code compiles without errors or warnings.
• All examples work.
• cargo fmt was run.
• Your changes were added to the CHANGELOG.md in the proper section.
• You updated existing examples or added examples (if applicable).
• Added examples are checked in CI

Nice to have

• You add a description of your work to this PR.
• You added proper docs for your newly added features and code.

Removes chip-specific references, briefly describes esp-hal tree, and adds quickstart.
closes #1224

[MabezDev]

I have some quite nitpicky comments (sorry!) that I think we should address.

Overall it looks okay but I think we should expand on the features of the HAL, for example, should mention that we support async. I would also link to the the LP hal for LP support core support. I would also link to esp-wifi for wifi/ble support.

[bjoernQ]

Given the README will be on crates.io (forgot about that first) maybe we should "borrow" some ideas and get inspiration from other HALs - e.g. https://crates.io/crates/embassy-stm32

[jessebraham]

Just a few nitpicks, thanks for taking care of this!

[SergioGasquez]

Regarding format, might be worth to try following the style guide that we wrote for the book: https://github.com/esp-rs/book/blob/main/rust-doc-style-guide.md. I've just used the vale config created from those rules and here is the output:

❯ vale esp-hal/README.md --config /home/sergio/Documents/Espressif/esp-vale-config/.vale.ini

 esp-hal/README.md
 1:3     warning     Use heading-style               Espressif-latest.Headings                   
                     capitalization. Capitalize                                                  
                     articles and prepositions of                                                
                     4 letters and less only at the                                              
                     beginning and end of heading                                                
                     title. See the rule's code for                                              
                     other exceptions.                                                           
 8:5     warning     Use heading-style               Espressif-latest.Headings                   
                     capitalization. Capitalize                                                  
                     articles and prepositions of                                                
                     4 letters and less only at the                                              
                     beginning and end of heading                                                
                     title. See the rule's code for                                              
                     other exceptions.                                                           
 15:14   suggestion  Consider removing 'closely'.    Espressif-latest.Adverbs                    
 15:242  error       Use 'Wi-Fi' instead of 'WiFi'.  Espressif-latest.TermsSingleCorrectSpelling 
 22:4    warning     Use heading-style               Espressif-latest.Headings                   
                     capitalization. Capitalize                                                  
                     articles and prepositions of                                                
                     4 letters and less only at the                                              
                     beginning and end of heading                                                
                     title. See the rule's code for                                              
                     other exceptions.                                                           
 47:5    warning     Use heading-style               Espressif-latest.Headings                   
                     capitalization. Capitalize                                                  
                     articles and prepositions of                                                
                     4 letters and less only at the                                              
                     beginning and end of heading                                                
                     title. See the rule's code for                                              
                     other exceptions.                                                           
 62:1    suggestion  Try to keep sentences short (<  Microsoft.SentenceLength                    
                     30 words).   

✖ 1 error, 4 warnings and 2 suggestions in 1 file.

Most of the things are not relevant Id say

[MabezDev]

Regarding format, might be worth to try following the style guide that we wrote for the book: https://github.com/esp-rs/book/blob/main/rust-doc-style-guide.md. I've just used the vale config created from those rules and here is the output:

❯ vale esp-hal/README.md --config /home/sergio/Documents/Espressif/esp-vale-config/.vale.ini

 esp-hal/README.md
 1:3     warning     Use heading-style               Espressif-latest.Headings                   
                     capitalization. Capitalize                                                  
                     articles and prepositions of                                                
                     4 letters and less only at the                                              
                     beginning and end of heading                                                
                     title. See the rule's code for                                              
                     other exceptions.                                                           
 8:5     warning     Use heading-style               Espressif-latest.Headings                   
                     capitalization. Capitalize                                                  
                     articles and prepositions of                                                
                     4 letters and less only at the                                              
                     beginning and end of heading                                                
                     title. See the rule's code for                                              
                     other exceptions.                                                           
 15:14   suggestion  Consider removing 'closely'.    Espressif-latest.Adverbs                    
 15:242  error       Use 'Wi-Fi' instead of 'WiFi'.  Espressif-latest.TermsSingleCorrectSpelling 
 22:4    warning     Use heading-style               Espressif-latest.Headings                   
                     capitalization. Capitalize                                                  
                     articles and prepositions of                                                
                     4 letters and less only at the                                              
                     beginning and end of heading                                                
                     title. See the rule's code for                                              
                     other exceptions.                                                           
 47:5    warning     Use heading-style               Espressif-latest.Headings                   
                     capitalization. Capitalize                                                  
                     articles and prepositions of                                                
                     4 letters and less only at the                                              
                     beginning and end of heading                                                
                     title. See the rule's code for                                              
                     other exceptions.                                                           
 62:1    suggestion  Try to keep sentences short (<  Microsoft.SentenceLength                    
                     30 words).   

Most of the things are not relevant Id say

Oh that's really nice! Do you know if we can run this in CI 👀. Maybe that's not worth the effort though.

[SergioGasquez]

Oh that's really nice! Do you know if we can run this in CI 👀. Maybe that's not worth the effort though.

That was the idea, at least for the books/trainings, but so far it's not possible as the repo with vale rules is under GitLab and its closed-source. I've had some conversations about how to use it on CI, but I haven't heard any update regarding this in the last months, I'll try to get an update.

[jessebraham]

I think prose linting our READMEs in CI is probably barbaric overkill, but can we move this to a discussion or something instead please, so the conversation doesn't disappear with this PR.

[bjoernQ]

Would be good if the usage paragraph would link to the (not merged yet) README for the examples ( #1237 ) - not sure if we then want or should have the command to run examples duplicated or not

[jessebraham]

I've had my way with this file now, so LGTM 😁