Added RTD setup files

[atteggiani]

• Updated GitHub pages deployment workflows
• Added RTD config
• Added link-checking
• Updated ci.yml to prevent it from running when only files related to documentation are changed

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[github-actions]

PR Preview
🚀 Preview of PR head commit 96800cf deployed to http://access-experiment-generator.access-hive.org.au/pr-previews/74
2025-11-28 11:00 AEDT
Preview generated through the Deploy to GitHub Pages workflow run 19750260538.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 92.14%. Comparing base (466026b) to head (96800cf).

Additional details and impacted files

@@           Coverage Diff           @@
##             main      #74   +/-   ##
=======================================
  Coverage   92.14%   92.14%           
=======================================
  Files          19       19           
  Lines         764      764           
  Branches      182      182           
=======================================
  Hits          704      704           
  Misses         30       30           
  Partials       30       30           

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[minghangli-uni]

@dougiesquire could you please review this PR when you are available?