RCAL-806: FY24 Datamodels Document Review

[PaulHuwe]

Resolves RCAL-806

Closes #386 #341

This PR updates the documentation to match the present code version.

Tasks

• Update or add relevant roman_datamodels tests.
• Update relevant docstrings and / or docs/ page.
• Does this PR change any API used downstream? (If not, label with no-changelog-entry-needed.)
  • Write news fragment(s) in changes/: echo "changed something" > changes/<PR#>.<changetype>.rst (see below for change types).
  • Start a romancal regression test (https://github.com/spacetelescope/RegressionTests/actions/workflows/romancal.yml) with this branch installed ("git+https://github.com/<fork>/rad@<branch>").

News fragment change types:

• changes/<PR#>.feature.rst: new feature
• changes/<PR#>.bugfix.rst: fixes an issue
• changes/<PR#>.doc.rst: documentation change
• changes/<PR#>.removal.rst: deprecation or removal of public API
• changes/<PR#>.misc.rst: infrastructure or miscellaneous change

[schlafly]

This looks good to me. IIRC Brett just removed assignment validation from roman_datamodels so I don't think we should document that bit.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 97.34%. Comparing base (087a60d) to head (e44083e).
Report is 84 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #437      +/-   ##
==========================================
- Coverage   97.56%   97.34%   -0.22%     
==========================================
  Files          30       37       +7     
  Lines        2788     3317     +529     
==========================================
+ Hits         2720     3229     +509     
- Misses         68       88      +20     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[braingram]

LGTM. Thanks for all the fixes.