Write V2 'Layout' first week experience page

[ericwindmill]

Page URL

https://docs.flutter.dev/get-started/fwe/layout

Page source

No response

Describe the problem

The current page is a list a links, which was the goal for V1 of FWE. The goal of V2 is to have more of the concepts are explained on the page directly.

Expected fix

• Explain constraints and box types on the page, including necessary diagrams and code examples.
• Show an example of using single-child layout widgets on the page, including diagrams and text that explains the example.
• Show an example of using flex widgets (rows and columns) on the page, including diagrams and text that explains the example.
  • Explain alignment, sizing and using Expanded within Flex widgets
• Explain unbound constraints bug, and use it as an example to explain devtools and debugging
• Show an example of using scrolling widgets on the page, including diagrams and text that explains the example.
• Show an example of the builder pattern on the page, including diagrams and text that explains the example.
• For all above explanations, remove outbound links to redundant resources

Additional context

No response

I would like to fix this problem.

• I will try and fix this problem on docs.flutter.dev.