ci) add gitea actions and refresh readme

.gitea/workflows/main-image.yml

@@ -0,0 +1,43 @@
+name: Build and Push Image
+
+on:
+  push:
+    branches:
+      - main
+
+env:
+  REGISTRY_HOST: git.campbellwireless.net
+  IMAGE_NAME: ${{ github.repository }}
+
+jobs:
+  docker-build-and-push:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Setup Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Log in to Gitea registry
+        uses: docker/login-action@v3
+        with:
+          registry: ${{ env.REGISTRY_HOST }}
+          username: ${{ secrets.REGISTRY_USERNAME }}
+          password: ${{ secrets.REGISTRY_PASSWORD }}
+
+      - name: Compute image tags
+        id: tags
+        run: |
+          echo "sha_short=$(echo '${{ github.sha }}' | cut -c1-12)" >> "$GITHUB_OUTPUT"
+
+      - name: Build and push image
+        uses: docker/build-push-action@v6
+        with:
+          context: .
+          file: ./Dockerfile
+          push: true
+          tags: |
+            ${{ env.REGISTRY_HOST }}/${{ env.IMAGE_NAME }}:latest
+            ${{ env.REGISTRY_HOST }}/${{ env.IMAGE_NAME }}:${{ steps.tags.outputs.sha_short }}