ci: Add release automation

.github/workflows/release.yml

@@ -0,0 +1,30 @@
+name: Release
+
+on:
+  push:
+    tags:
+      - "*"
+  workflow_dispatch:
+
+jobs:
+  release:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-node@v1
+        with:
+          node-version: 16
+      - run: npm ci
+      - name: Publish to Open VSX Registry
+        uses: HaaLeo/publish-vscode-extension@v1
+        id: publishToOpenVSX
+        with:
+          pat: ${{ secrets.OPEN_VSX_TOKEN }}
+          skipDuplicate: true
+      - name: Publish to Visual Studio Marketplace
+        uses: HaaLeo/publish-vscode-extension@v1
+        with:
+          pat: ${{ secrets.VS_MARKETPLACE_TOKEN }}
+          registryUrl: https://marketplace.visualstudio.com
+          extensionFile: ${{ steps.publishToOpenVSX.outputs.vsixPath }}
+          skipDuplicate: true