Reorganization of the documentation folder

[lionelkusch]

I moved the configuration and other tools of the documentation into a side folder.
I updated the way the files are generated.

I did this in a way of not mixing the documentation itself with the file for generating it.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 99.69%. Comparing base (a7945ab) to head (0847dad).

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #304   +/-   ##
=======================================
  Coverage   99.69%   99.69%           
=======================================
  Files          19       19           
  Lines         987      987           
=======================================
  Hits          984      984           
  Misses          3        3           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[bthirion]

Looks mostly good, thx.

[jpaillard]

I am a bit lost and would not know where to find what.
Can we add a markdown file with the repo's folder architecture? And where to find what? It could, for instance be in the documentation_developer

[jpaillard]

Ok, I'll follow-up on #307

[bthirion]

LGTM, thx.