Build and setup Squid in SPO guide

[jpraynaud]

Content

This PR includes...

Pre-submit checklist

• Branch
  • [ ] Tests are provided (if possible)
  • [ ] Crates versions are updated (if relevant)
  • [ ] Commit sequence broadly makes sense
  • [ ] Key commits have useful messages
• PR
  • [ ] No clippy warnings in the CI
  • [ ] Self-reviewed the diff
  • [ ] Useful pull request description
  • [ ] Reviewer requested
• Documentation
  • [ ] Update README file (if relevant)
  • [ ] Update documentation website (if relevant)
  • [ ] Add dev blog post (if relevant)

Comments

Issue(s)

Relates to #YYY or Closes #YYY

[github-actions[bot]]

Test Results

    3 files  ±0     43 suites  ±0   8m 35s :stopwatch: -1s   979 tests ±0    979 :white_check_mark: ±0  0 :zzz: ±0  0 :x: ±0  1 073 runs  ±0  1 073 :white_check_mark: ±0  0 :zzz: ±0  0 :x: ±0 

Results for commit 1262fb78. ± Comparison against base commit 94a103c7.

:recycle: This comment has been updated with latest results.