Merge pull request #12 from voxpupuli/update_readme

update readme on how to build a container

README.md

@@ -6,3 +6,19 @@
 This project hosts the Dockerfile and the required scripts to build a Puppet Server container image.
 
 For compose file see: [CRAFTY](https://github.com/voxpupuli/crafty)
+
+## How to build the container
+
+If you wanna build for example puppetserver 7.13.0, you can do it like this:
+Check the latest deb package version [here](https://apt.puppet.com/pool/jammy/puppet7/p/puppetserver/index.html). The container is Ubuntu 22.04 at the moment.
+
+If you checked the version and it is available as Ubuntu package, just create a tag and push it.
+
+```bash
+git tag 7.13.0
+git push --tags
+```
+
+The build will be triggerd on any new tag. The tag has to match the version, because it is used internally as version referrence.
+
+The build system watches for tags which begin with a 7 for puppet7-release and 8 for puppet8-release.