Proposal: Move user-event documentation here

[nickserv]

Is your feature request related to a problem? Please describe.

Some users either aren't aware about user-event because it's not mentioned by the documentation, or want to use it but find the documentation harder to find.

Describe the solution you'd like

Move at least the API documentation in user-event's readme to a prominent page in the sidebar of the docs. This should be in a format similar to fireEvent to make it easier to learn, but still in a separate section so users are aware they have to install another package. Overall, it should be clear that this is recommended, but still not actually a part of the other testing libraries.

Additional context

This could also make it easier to migrate user-event back into dom-testing-library in the future.

Related issues

• Why user-event,jest-dom are putting in small *ecosystem*? Those are de facto stuff within @testing-library/react as almost React devs. #515
• Elevate fire event page in prep for merge #502
• Unify "Firing Events" page #490

[MatanBobi]

I agree with this one,
I think that user-event is pretty much hidden and having the API in the docs site sounds like a good idea to me.

[nickserv]

There's already a user-event page in the docs, but there are still some differences between the docs page and the readme. In order to remove this content from user-event, we'll need to make sure they're in sync first.

Here's what I'm planning on doing:

• docs: update readme with changes in docs user-event#701
• docs: update docs for user-event from readme #892
• docs: move readme content to docs user-event#704
• Test anchor links
• Split up pages in docs
• Sync contributors
• Make docs library agnostic (replace react with dom, using installation docs as an example)
• Use getByRole with the second argument of selectOptions in docs for consistency