docs: updates legacy packages with info regarding their removal

[lukegalbraithrussell]

Summary

👋

Requirements

• I've read and understood the Contributing Guidelines and have done my best effort to follow them.
• I've read and agree to the Code of Conduct.

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⚠️ No Changeset found

Latest commit: 0f7d8f1

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 93.17%. Comparing base (7b26c3e) to head (0f7d8f1).
⚠️ Report is 1 commits behind head on p.
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@           Coverage Diff           @@
##                p    #2519   +/-   ##
=======================================
  Coverage   93.17%   93.17%           
=======================================
  Files          40       40           
  Lines       11384    11384           
  Branches      726      726           
=======================================
  Hits        10607    10607           
  Misses        765      765           
  Partials       12       12           

Flag	Coverage Δ
cli-hooks	95.42% <ø> (ø)
cli-test	94.79% <ø> (ø)
oauth	77.39% <ø> (ø)
socket-mode	61.87% <ø> (ø)
web-api	98.12% <ø> (ø)
webhook	96.66% <ø> (ø)

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[zimeg]

@lukegalbraithrussell Thanks so much for keeping references around! I'd imagine it's frustrating to find a missing package otherwise...

LGTM and no blockers from me, but I notice we also have a mention in our README and I wasn't sure if this should be removed perhaps? Or changed similar? Or left as is! 📚 ✨

node-slack-sdk/README.md

Lines 33 to 37 in 59df200

	**Deprecation Notice**
	`@slack/events-api` and `@slack/interactive-messages` officially reached EOL on May 31st, 2021. Development has fully stopped for these packages and all remaining open issues and pull requests have been closed.
	At this time, we recommend migrating to [Bolt for JavaScript](https://github.com/slackapi/bolt-js), a framework that offers all of the functionality available in those packages (and more). To help with that process, we've provided some [migration samples](https://docs.slack.dev/tools/node-slack-sdk/migration/migrating-to-v6/) for those looking to convert their existing apps.

[lukegalbraithrussell]

@zimeg I removed the README callout! imo readmes should reflect current state

[zimeg]

🏆 @lukegalbraithrussell LGTMs all around!

I'm curious if we can remove the "deprecated packages" section of the sidebar too, perhaps considering the suggestion to @slack/bolt as part of "migration" instead? No blocker since I'm not too familiar with these page rankings 🤓