[karshPrime]

Generated projects take their version from the release tags rather than a VERSION file, and this template publishes release notes in place of a changelog.

• generated projects ship the shared CI v4.0.0: CI works out each release's version from the commit messages and passes it to every make target
• release notes take in every pull request merged since the last release
• copier update removes VERSION from existing projects, and their tags carry on as before
• setuptools-scm reads the version from the tags, so generated projects keep no VERSION file
• CI's version reaches the build through the Makefile, so wheels and sdists carry the version being released
• a build without tags or without git reports 0.0.0
• each merge to main publishes a GitHub release, with the merged pull request's description as its notes, instead of only a tag
• the version comes from the commits since the last tag, the same way as in projects
• the README explains that versions come from commit messages and existing projects lose VERSION on update
• release notes on GitHub replace CHANGELOG.md, which is removed

[karshPrime]

Draft until karshosphere/template-github-ci#12 is merged and released as v4.0.0. Then this branch gets one more commit, feat!:, that brings in the new shared CI, removes template/VERSION and drops VERSION from _skip_if_exists. That commit is also what makes this release a major version. Merging before then would ship projects that still carry the old VERSION check.

[karshPrime]

template-github-ci v4.0.0 is released, and a5263cf brings it in: the shared CI v4.0.0, template/VERSION removed and VERSION dropped from _skip_if_exists. Ready for review.