ci: add release workflow with semver Docker tags and GitHub Releases

- New release.yml: triggers on v* tags, builds/pushes Docker with vX.Y.Z, vX.Y, vX, latest tags, creates GitHub Release with changelog
- Updated docker.yml: main pushes now tag as 'edge' (dev) instead of 'latest'
- latest tag is now only set by the release workflow on version tags

.github/workflows/docker.yml

@@ -3,6 +3,8 @@ name: Docker
 on:
   push:
     branches: [main]
+    tags-ignore:
+      - 'v*'
 
 jobs:
   build-and-push:
@@ -27,7 +29,7 @@ jobs:
         with:
           images: ghcr.io/${{ github.repository }}
           tags: |
-            type=raw,value=latest
+            type=raw,value=edge
             type=sha,prefix=
 
       - name: Build and push