Add branches to latest major versions

[docwhat]

Please consider adding a branch for each major version to allow easy linking to the correct documents and template. e.g., stable-1, stable-2, stable-3.

This would allow linking to (for example) the latest 2.x template without pulling in 3.x features until we are ready for them.

[koppor]

I read into https://www.atlassian.com/git/tutorials/comparing-workflows/gitflow-workflow and created the following branches (see https://github.com/adr/madr/branches for the complete list)

• main always having the latest release
• develop for development - homepage generated using netlify - hosted at https://develop--madr-develop.netlify.app/
• gh-pages for the homepage - being the stable homepage.
• releases/v1, releases/v2, releases/v3 tracking releases of (past) major versions. Will create develop/v1 and others as needed.

I looked at https://github.com/actions/setup-java for inspiration. They also seem to have "moving tags" for their major versions. I opted against it and keep the branches. There will be develop/v1 in case there is a fix for the old versions.

I think, this should solve the issue. If not, feel free to reopen.

[koppor]

I removed branch main, because it causes confusion. All development should be in develop. That name should make clear that it's not the release version.