fix(workflows): docs-preview and npm job

[jsjoeio]

This includes the GITHUB_TOKEN on the docs-preview.yaml workflow, which should fix it on forks I believe. I also added a step to the npm job to comment instructions for how to test the PR locally.

Fixes N/A

[github-actions]

✨ code-server docs for PR #5042 is ready! It will be updated on every commit.

• Host: https://coder.com/docs/code-server/34d2555
• Last deploy status: success
• Commit: 8e8406f
• Workflow status: https://github.com/coder/code-server/actions/runs/2066127120

[codecov]

Codecov Report

Merging #5042 (34d2555) into main (06e36b4) will not change coverage.
The diff coverage is n/a.

❗ Current head 34d2555 differs from pull request most recent head 8e8406f. Consider uploading reports for the commit 8e8406f to get more accurate results

@@           Coverage Diff           @@
##             main    #5042   +/-   ##
=======================================
  Coverage   71.30%   71.30%           
=======================================
  Files          30       30           
  Lines        1683     1683           
  Branches      373      373           
=======================================
  Hits         1200     1200           
  Misses        413      413           
  Partials       70       70           

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[github-actions]

✨ code-server dev build published to npm for PR #5042!

• Last publish status: success
• Commit: 8e8406f

To install in a local project, run:

npm install @coder/code-server-pr@5042

To install globally, run:

npm install -g @coder/code-server-pr@5042

[code-asher]

Handy!