docs: make collections more accessible in docs

[iCrawl]

Please describe the changes this PR makes and why it should be merged:

This does come with the drawback that we remove the actual documentation on the class itself but since it was an empty page, I don't really see how it was beneficial to us in the first place.

Fixes #3896

Status

• Code changes have been tested against the Discord API, or there are no code changes
• I know how to update typings and have done so, or typings don't need updating

Semantic versioning classification:

• This PR changes the library's interface (methods or parameters added)
  • This PR includes breaking changes (methods removed or renamed, parameters moved or removed)
• This PR only includes non-code changes, like changes to documentation, README, etc.