fix(release): bump version badge in root README.md on every push to main

[Copilot]

release.yml was updating the version in cli/__version__.py, CHANGELOG.md, and hugo-docs/content/_index.md but skipping the version badge in the root README.md, leaving it permanently stale.

Changes

• New step — "Update version badge in root README" applies the same sed substitution already used for the Hugo docs index:

  sed -i -E \
    "s|version-[0-9]+\.[0-9]+\.[0-9]+-blue|version-${NEW_VERSION}-blue|g" \
    README.md

• add-paths — README.md added to the peter-evans/create-pull-request step so the file is committed in the automated version-bump PR
• PR body — updated to reflect that README.md is now part of the automated bump

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[chefgs]

@copilot please review the changes

[Copilot]

@copilot please review the changes

Here's a review of the changes in this PR (commit 19d0ad9):

What was broken: release.yml bumped the version in cli/__version__.py, CHANGELOG.md, and hugo-docs/content/_index.md on every push to main, but never touched README.md — leaving its version badge permanently stale.

What was changed:

1. New step 4 — "Update version badge in root README"
   Uses the exact same sed substitution already in place for the Hugo docs:

   sed -i -E \
     "s|version-[0-9]+\.[0-9]+\.[0-9]+-blue|version-${NEW_VERSION}-blue|g" \
     README.md

   This targets only the shields.io badge URL pattern, so it's safe — it won't accidentally touch version strings elsewhere in the README.

2. add-paths in create-pull-request — README.md added so the file is included in the automated version-bump commit/PR.

3. PR body — updated to document that README.md is now part of each automated bump.

No other behaviour changed. The step ordering (1→2→3→4→5→6) is sequential and correct. The if: guard that prevents infinite loops remains untouched. The tag step still fires only when the PR is successfully created.