Add documentation on installation & resource managers + example
Add documentation for authorization checker
Add documentation for frontend manager
Add documentation about using FrontendManager in a custom controller
Look in 2 places for the autoloader

Look for the autoloader where it would be if the library is taken as project root,
and the place where it would be if the library is installed by composer as a dependency
Add link to documenation for develop
Merge branch 'feature/docs' into develop

* feature/docs:
  Add link to documenation for develop
  Add documentation about using FrontendManager in a custom controller
  Add documentation for frontend manager
  Add documentation for authorization checker
  Add documentation on installation & resource managers + example