Add first PR check

To be followed by tests and `npm run build`, obviously!

.gitea/workflows/pr.yaml

@@ -0,0 +1,23 @@
+name: PR Checks
+
+on:
+  pull_request:
+    branches:
+      - main
+
+jobs:
+  pr-checks:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Install Node
+        run: |
+          apt-get update && apt-get install -y nodejs
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          # super-linter needs the full git history to get the
+          # list of files that changed across commits
+          fetch-depth: 0
+
+      - name: Super Linter
+        uses: super-linter/super-linter@v7.3.0