- Prettier changelog
- Link to examples on frontpage
- Link to wiki on frontpage
- Put telegram.ext in own sidebar thingy

Superseeds #1089
- Remove `:obj:Filter` as it's pretty obvious that it's a filter since it's in this module. It also made the html output about 1/3 times longer to scroll through.
- Add an __all__ to reorder so Filter is at the top instead of BaseFilter
- Add a proper docstring for document that documents the attributes (this is the #1089 part)
- Also fix a couple of grammar errors.