This repo demonstrates a simple implementation of using Git tags to version a repo and create GitHub releases.
The VERSION file holds the version info. On a push to main, the tag workflow creates and pushes a git tag with the version. On a successful run of the tag workflow, the release workflow creates a GitHub release with the tag.
Semantic Versioning is used for the versioning system. A version number is made up of MAJOR.MINOR.PATCH. Essentially, a major release is created when a breaking change is introduced, a minor release is created when a new feature is introduced, and a patch release is created for bugfixes, small updates, and anything else.
Every pull request should update the value in the VERSION file. If you are not sure when you should tag your project with version 1.0.0, this version should be when it is ready to be used by your "customer" (another dev, project, or external client).