feat: docker build and gitea workflow

.gitea/workflows/build.yml

@@ -0,0 +1,30 @@
+name: Build and Push Docker Image
+
+on:
+  push:
+    branches:
+      - beta
+  workflow_dispatch:
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Log in to Gitea Container Registry
+        uses: docker/login-action@v3
+        with:
+          registry: git.pihkaal.me
+          username: ${{ secrets.REGISTRY_USERNAME }}
+          password: ${{ secrets.REGISTRY_PASSWORD }}
+
+      - name: Build and push Docker image
+        run: |
+          docker build -t git.pihkaal.me/pihkaal/pihkaal-me:latest .
+          docker push git.pihkaal.me/pihkaal/pihkaal-me:latest