feat(mdatagen): add automatic feature gate documentation generation

[sAchin-680]

Description

Implements automatic documentation generation for component feature gates via mdatagen.

Component authors can now declare feature gates in metadata.yaml, and mdatagen will automatically generate standardized markdown documentation including gate IDs, stages, descriptions, version information, and reference links.

Key Changes:

• Extended metadata-schema.yaml with feature_gates section
• Added FeatureGate types with validation (required fields, valid stages, version format)
• Created documentation template rendering feature gates as markdown table
• Integrated into existing documentation generation pipeline
• Added test coverage and usage documentation

Link to tracking issue

~~Fixes~~ (edit by @mx-psi) Updates #14067

Testing

• All 282 tests passing
• Added TestRunContents/feature_gates.yaml test case
• Validated documentation generation and error handling
• Lint checks passing

Documentation

• Added "Feature Gates Documentation" section to cmd/mdatagen/README.md with usage examples
• Generated example visible in cmd/mdatagen/internal/testdata/documentation.md

[linux-foundation-easycla[bot]]

The committers listed above are authorized under a signed CLA.

• :white_check_mark: login: sAchin-680 / name: SACHIN KUMAR (0d5f5579ba99482b81bdec2e2daa70febeaff731, 1bf8cd695dbf8531b1f860a31388e26e8b428297, 2bdcaedcd5aba3cfb2bd4a3fadf8a217bfbc2771, 548f80eabe471c4236757e80f473ea988bb8092e, b0b6fcaad13c345f46e15e3bf2321dd5520780ec, b6e64cecba573cac7de87a6ad4c80ac747e429d1, e5207d941d3be8156e7a77a688da26011e459549, f83b3305ef10a74037fe87ea97cdf0adf2eee14a)

[codecov[bot]]

Codecov Report

:x: Patch coverage is 94.87179% with 2 lines in your changes missing coverage. Please review. :white_check_mark: Project coverage is 92.14%. Comparing base (2e9c827) to head (b6e64ce). :warning: Report is 28 commits behind head on main.

Files with missing lines	Patch %	Lines
cmd/mdatagen/internal/metadata.go	94.73%	1 Missing and 1 partial :warning:

:x: Your patch check has failed because the patch coverage (94.87%) is below the target coverage (95.00%). You can increase the patch coverage or adjust the target coverage.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #14130      +/-   ##
==========================================
- Coverage   92.15%   92.14%   -0.02%     
==========================================
  Files         666      666              
  Lines       41441    41479      +38     
==========================================
+ Hits        38191    38219      +28     
- Misses       2213     2219       +6     
- Partials     1037     1041       +4     

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[sAchin-680]

Done in f92d1f8!

• Ran make gogenerate,
• Added 'mycomponent' to metadata-schema.yaml status.class,
• Added 'mycomponent' to cspell.json,
• Reverted all autoformatting changes - now only 2 clean additions vs main (no IDE formatting)

The schema file now has zero unrelated changes.

[sAchin-680]

Thanks @sAchin-680! Looks like just a space in the generated file's import list and it should be good to go to pass the CI checks

Hey @codeboten. Fixed the import spacing in generated_package_test.go. Should be good to go now.

[github-actions[bot]]

This PR was marked stale due to lack of activity. It will be closed in 14 days.