Add base map code

This was built with `npm create ol-app my-app`.

.github/workflows/build.yml

@@ -0,0 +1,32 @@
+name: Build
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    branches:
+      - main
+
+env:
+  CI: true
+
+jobs:
+  build:
+    name: Build
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Clone Repository
+        uses: actions/checkout@v3
+
+      - name: Set Node.js Version
+        uses: actions/setup-node@v3
+        with:
+          node-version: 16
+
+      - name: Install Dependencies
+        run: npm ci
+
+      - name: Build
+        run: npm run build