Explain docker image tags

Author: defnull

.github/workflows/docker.yaml

@@ -26,6 +26,7 @@ jobs:
         with:
           images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
           tags: |
+            type=raw,value=latest,enable={{is_default_branch}}
             type=ref,event=branch
             type=semver,pattern={{version}}
             type=semver,pattern={{major}}.{{minor}}

README.md

@@ -50,10 +50,18 @@ BBBLB is currently in a **pre-alpha state**. It is a working prototype and **not
 
 The documentation is still a work in progress. Pull requests are very welcomed!
 
-# Deployment and Getting Started
+## Deployment and Getting Started
 
 To get started, check out the docker compose based deployment example in [examples/bbblb-compose](https://github.com/defnull/bbblb/blob/main/examples/bbblb-compose) and refer to [examples/bbblb-compose/README.md](https://github.com/defnull/bbblb/blob/main/examples/bbblb-compose/README.md) for a step by step instructions.
 
+Docker images are available via `ghcr.io`:
+
+* `ghcr.io/defnull/bbblb:main` Main branch
+* `ghcr.io/defnull/bbblb:latest` Whatever tag pushed last. DO NOT USE as this can jump to older maintenance releases at the moment.
+* `ghcr.io/defnull/bbblb:X` Latest minor or patch release for the major version `X` (e.g. `1`)
+* `ghcr.io/defnull/bbblb:X.Y` Latest patch release for the minor version `X.Y` (e.g. `1.2`)
+* `ghcr.io/defnull/bbblb:X.Y.Z` A specific patch release `X.Y.Z` (e.g. `1.2.3`)
+
 Manual deployments without docker are of cause also possible. The most complex part is not BBBLB, but the front-ent http server to get presentation playback to work. We will provide documentation in the future, pull requests are very welcomed.
 
 ## Configuration Options