[doc] chore: update last_updated

[adangel]

Describe the PR

Add a little helper script to determine the last_updated date from the git info. This script is intended to be run manually every so often.

I tried to add https://github.com/klandergren/jekyll-last-commit but this was too slow (e.g. waiting 5 minutes after any change in serving mode).

So, this is the least invasive method I could come up with.

It has some false positives (e.g. it would try to update

pmd/docs/pages/pmd/devdocs/major_contributions/adding_a_new_antlr_based_language.md

Line 257 in 4b7f76c

last_updated: <Month> <Year> (<PMD Version>)

...).
And it can't determine the version number for changes done in the current version.

So, at this stage, it is not something, we can run automatically.

I could solve the false positives. If I run the script again, no further changes to files are made, which means, all "last_updated" fields are correct now. So, this script could indeed be run automatically somewhere...

Related issues

• Fix #

Ready?

• Added unit tests for fixed bug/feature
• Passing all unit tests
• Complete build ./mvnw clean verify passes (checked automatically by github actions)
• Added (in-code) documentation (if needed)

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No regression tested rules have been changed.

(comment created at 2026-01-07 07:47:57+00:00 for e96320d)