Add architecture part in the Whitepaper

[antho31]

Here's the first version of the "Architecture" section of the whitepaper.

• Overall architecture (updated schema since our meeting on June 14)
• Mermaid sequence diagram from the end-to-end example

Note that texts and schemas have not been fully validated. There are some fuzzy points. It may be worth publishing this to help developers for the Builders Program...

What are your points?

[ccamel]

Great job. I left some comments. There are indeed some inaccuracies and uncertainties in some paragraphs that need to be addressed. We can have a meeting to discuss them together, with @amimart.

[amimart]

Thanks !

Here's a first review, I didn't check everything in details though :)

[MdechampG]

Thank you @antho31 ! Here are few typos.

[antho31]

Thanks, @amimart & @MdechampG, for your complete and relevant feedback! The last commit integrates all the suggested changes, it includes updated schemas too.

[antho31]

Updated with schemas from Lisa.
Can we publish this new part of the WP?