fix: add Dockerfile and gitea ci pipeline

.gitea/workflows/publish-docker.yml

@@ -0,0 +1,46 @@
+---
+name: Build and Publish Docker Image
+on:
+  push:
+    branches:
+      - main
+    tags:
+      - 'v*'
+
+jobs:
+  build-and-push:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Log in to Gitea Container Registry
+        uses: docker/login-action@v3
+        with:
+          registry: git.br0tkasten.de
+          username: ${{ gitea.actor }}
+          # access token of the user triggering this action
+          # in gitea -> user settings -> applications -> new token -> write:packages and write:repositories
+          # then in gitea -> user settings -> actions -> secrets -> add new secret named "TOKEN" with the value of the access token.
+          password: ${{ secrets.TOKEN }} 
+
+      - name: Extract metadata (tags, labels) for Docker
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: git.br0tkasten.de/${{ gitea.repository }}
+          flavor: |
+            latest=true
+          tags: |
+            type=ref,event=branch
+            type=semver,pattern={{version}}
+            type=sha
+
+      - name: Build and push Docker image
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          push: true
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
+