chore: add deprecation notice

[vasco-santos]

In the context of the async refactor in [email protected], this modules is being deprecated.
For immediate alternatives, you should use libp2p/js-libp2p-webrtc-star. Meanwhile, you should follow libp2p/js-libp2p#385, as I am currently working on this vertical.

Needs:

• npm deprecation notice

After merged, the repo must be archived

[jacobheun]

I think we should wait to archive the repo. The notices are fine, but as there are people still using this quite a bit, we should allow some more time to upgrade before archiving in case any patches are needed.

[vasco-santos]

I agree! That's why I also did not merge libp2p-keychain and peer-info...
How should we proceed? I suggest that we merge the PRs and do the deprecation notices and we define a date for archiving and create an issue to track that.

[jacobheun]

I suggest that we merge the PRs and do the deprecation notices and we define a date for archiving and create an issue to track that.

sgtm, we can discuss timeline in the issue.

[lidel]

LGTM, but in my experience people often skip stuff when scanning READMEs.
I tweaked deprecation notice to be more prominent (based on this) – hope thats okay :)

btw: someone with admin rights should also update description, example: