Add Helm chart for Vikunja with templates, ignore files, and CI workflow

.gitea/workflows/chart.yaml

@@ -0,0 +1,28 @@
+name: Helm Chart Build and Publish
+on:
+  push:
+    branches:
+      - master
+
+jobs:
+  build-and-publish:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v2
+
+      - name: Set up Helm
+        run: |
+          curl https://raw.githubusercontent.com/helm/helm/main/scripts/get-helm-3 | bash
+
+      - name: Build Helm Chart
+        run: |
+          helm package . --destination ./charts
+
+      - name: Publish Helm Chart to registry
+        env:
+          HELM_REGISTRY: "https://git.leece.im/api/packages/${{ secrets.REGISTRY_USERNAME }}/helm/api/charts"
+          USERNAME: ${{ secrets.REGISTRY_USERNAME }}
+          PASSWORD: ${{ secrets.REGISTRY_PASSWORD }}
+        run: |
+          curl --user $USERNAME:$PASSWORD -X POST --upload-file ./charts/*.tgz $HELM_REGISTRY