Add check docs

[BrunoQuaresma]

In the long term, we want to add a "broken link checker," but for now, it should solve our issue with broken docs.

[codecov]

Codecov Report

Merging #4047 (5239dbc) into main (070a122) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main    #4047   +/-   ##
=======================================
  Coverage   63.51%   63.51%           
=======================================
  Files          36       36           
  Lines        1872     1872           
  Branches      379      379           
=======================================
  Hits         1189     1189           
  Misses        580      580           
  Partials      103      103           

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[github-actions]

✨ Coder.com for PR #4047 deployed! It will be updated on every commit.

• Host: https://codercom-gltr46w42-codercom.vercel.app/docs/code-server
• Last deploy status: success
• Commit: 5239dbc
• Workflow status: https://github.com/cdr/code-server/actions/runs/1171680704

[BrunoQuaresma]