feat: add semantic-release with conventional commits

[joris974]

Summary

• Add semantic-release configuration (.releaserc.yaml) with conventionalcommits preset, NPM publish, and GitHub release plugins
• Add release.yml workflow using cycjimmy/semantic-release-action@v6.0.0
• Support rc/* branches for pre-releases
• Add RELEASE.md with conventional commit instructions
• Add release section to README.md

Prerequisites

Before merging, ensure:

• NPM_TOKEN secret is configured on the repo for NPM publishing
• Repository rulesets have a bypass configured for the release bot (if applicable)

Test plan

• Verify YAML syntax is valid for .releaserc.yaml and release.yml
• Confirm CI workflow passes on this PR
• After merge, verify a release is triggered with the feat: commit prefix
• Test pre-release flow by pushing to an rc/* branch

Mirrors freckle/i18n-scripts-js#21

[mjgpy3]

Changes seem fine. Are we standardizing on semantic commits?

[joris974]

Changes seem fine. Are we standardizing on semantic commits?

Yes. Pat made a great read on it: https://illuminate.atlassian.net/wiki/spaces/PENG/pages/17952735277/Semantic+Release