docs: add note about npm logging

[jsjoeio]

Fixes #3896

[codecov]

Codecov Report

Merging #4032 (3ba5154) into main (1d8806f) will not change coverage.
The diff coverage is n/a.

❗ Current head 3ba5154 differs from pull request most recent head 5b6db90. Consider uploading reports for the commit 5b6db90 to get more accurate results

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##             main    #4032   +/-   ##
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  Coverage   63.51%   63.51%           
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  Files          36       36           
  Lines        1872     1872           
  Branches      379      379           
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  Hits         1189     1189           
  Misses        580      580           
  Partials      103      103           

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[github-actions]

✨ Coder.com for PR #4032 deployed! It will be updated on every commit.

• Host: https://codercom-akjzgj5g8-codercom.vercel.app/docs/code-server
• Last deploy status: success
• Commit: 5b6db90
• Workflow status: https://github.com/cdr/code-server/actions/runs/1164393999

[jawnsy]

Suggested change

	Unfortunately, `yarn` swallows all logs on `yarn global add` so instead you can install with `npm` and see the logs:
	`yarn` suppresses logs when running `yarn global add`, so to debug installation issues, install with `npm` instead:

[jsjoeio]

oh noo! I didn't get a chance to add this because I hit "enable auto-merge" - I'll follow up with a PR