Add GH action for svelte-check

Author: rgossiaux

.github/workflows/check.yml

@@ -0,0 +1,19 @@
+name: svelte-check
+
+on:
+  push:
+    branches: [master]
+  pull_request:
+    branches: [master]
+  workflow_dispatch:
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: Install dependencies
+        run: npm install
+      - name: Run svelte-check
+        run: npm run check -- --use-new-transformation
+