[doc] multiple doc upgrades:
- Add Apycot architecture specification. Remove deprecated file.
- Add Apycot quick start tutorial which replaces the French step by step
- integrate old doc and remove deprecated files
- Update checkers doc
<toc>
<section resource="apycot_quick_start">
<title xml:lang="en">Apycot Quick Start</title>
</section>
<section resource="apycot_checker">
<title xml:lang="en">Available Checkers</title>
<title xml:lang="fr">Checkers Disponibles</title>
</section>
<section resource="apycot_architecture">
<title xml:lang="en">Architecture</title>
</section>
</toc>