Adds GH job to publish the VSCode ext to Marketplace and OpenVSX

.github/workflows/publish-vscode-extension.yaml

@@ -0,0 +1,45 @@
+name: Publish VSCode extension to Marketplace and OpenVSX
+
+on:
+  # Only allow this workflow manually from the Actions tab
+  workflow_dispatch:
+
+env:
+  NODE_OPTIONS: '--max_old_space_size=4096'
+
+jobs:
+  publish-vscode-extension:
+    name: 'Publish VSCode extension to Marketplace and OpenVSX'
+    environment: publish-vscode-extension
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+
+      - uses: actions/setup-node@v3
+        with:
+          node-version: '18'
+
+      - name: Setup antlr4
+        uses: ./.github/actions/setup-antlr4
+
+      - name: Install dependencies with frozen lock file
+        run: npm ci
+
+      - name: Build all packages
+        run: npm run build
+
+      - name: Publish to VSCode Marketplace
+        env:
+          VSCE_PAT: ${{ secrets.VSCE_PAT }}:
+        run: |
+          cd packages/vscode-extension
+          npx vsce package
+          npx vsce publish
+
+      - name: Publish to OpenVSX
+        env:
+          VSX_PAT: ${{ secrets.VSX_PAT }}: 
+        run: npx ovsx publish -p $VSX_PAT
+
+