Ops: Add a CI workflow

.github/workflows/ci.yaml

@@ -0,0 +1,42 @@
+name: CI
+on: [push]
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Begin CI...
+        uses: actions/checkout@v3
+
+      - name: Use Node 20
+        uses: actions/setup-node@v3
+        with:
+          node-version: 20.x
+
+      - name: Use cached node_modules
+        uses: actions/cache@v3
+        with:
+          path: node_modules
+          key: nodeModules-${{ hashFiles('**/pnpm-lock.yaml') }}
+          restore-keys: |
+            nodeModules-
+
+      - name: Install dependencies
+        run: pnpm install --frozen-lockfile
+        env:
+          CI: true
+
+      - name: Lint
+        run: pnpm lint
+        env:
+          CI: true
+
+      - name: Test
+        run: pnpm test:run --coverage --maxWorkers=2
+        env:
+          CI: true
+
+      - name: Build
+        run: pnpm build
+        env:
+          CI: true