Update directory structure documentation

[wojtekn]

Related issues

• Fixes https://github.com/Automattic/dotcom-forge/issues/10432

Proposed Changes

• I propose to add more details on the Studio directory structure.

Testing Instructions

• Review if changes are clear and correct: code-contributions.md

Pre-merge Checklist

• Have you checked for TypeScript, React or other console errors?

[nightnei]

LGTM 👍
I won't move in to "Reviewer approved", so that other team members could take a look ad say their objections, of they have.

[fredrikekelund]

LGTM with some small comments.

Should we use this opportunity to remove the ### CLI Development part from this doc? We don't officially support that stuff yet, so it seems confusing to include it in the docs.

[fredrikekelund]

How do we deal with module specific Redux stores..? Have we discussed that?

I would keep everything in the src/stores folder, and I guess you could argue that this makes sense because Redux state is inherently global.

So, I'm OK with the structure as currently proposed, but still wanted to bring this up for discussion.

[wojtekn]

We decided to have only global Redux stores.

[wojtekn]

Should we use this opportunity to remove the ### CLI Development part from this doc? We don't officially support that stuff yet, so it seems confusing to include it in the docs.

It says it's only for development, so I don't see anything against keeping it there.