Autogenerate .rst file generation - #5323

Closes #5309

There is now no longer a need to manually write out the .rst files! This PR also organizes the remaining .rst files into their respective categories, e.g. ext, or examples.

Docs for classes which used private bases like _BaseThumbedMedium have been changed temporarily to follow the same pattern as the normal telegram classes. This was done because #5279 will eliminate them and it makes this implementation easier if we don't have to account for it.

api_docs.py is where the logic lives, and was largely AI generated, but I did refine it over many prompts until my satisfaction for readability and maintainability.

TODO:

• Autogen pages should not be checked into git, should probably go into a separate gitignored directory
• Update roolsbot and other links to link to the new examples URL correctly. (Have the PR ready, merge just before v23 is released)
• Merge only after the dataclasses implementation!