Suggestion: Add versioned Docker tags (semver / commit SHA) instead of only master

[gregpavl]

Hi 👋

First of all, thanks for maintain the timeoff management project.

I noticed that the Docker image published to Docker Hub currently exposes only the master tag.
Since Docker tags are mutable, this makes it hard to safely pin the image in production
(a rebuild of master can unintentionally break downstream users).

Would you consider publishing additional immutable tags, for example:

• SemVer tags on releases (1.2.3, 1.2)
• Commit-based tags (sha-<short-commit>)
• Keeping master as a moving/edge tag

This would allow users to:

• Safely pin a known-good image
• Roll back easily
• Still benefit from the master tag for development

Thanks again!