feat: add CI workflow for automated testing and type checking

Author: lollipop-onl

.github/workflows/ci.yml

@@ -0,0 +1,30 @@
+name: CI
+
+on:
+  push:
+  pull_request:
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Setup pnpm
+        uses: pnpm/action-setup@v4
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: '20'
+          cache: 'pnpm'
+
+      - name: Install dependencies
+        run: pnpm install --frozen-lockfile
+
+      - name: Run type check
+        run: pnpm exec tsc --noEmit
+
+      - name: Run tests
+        run: pnpm test:run

README.md

@@ -1,3 +1,5 @@
 # Backlog Unfurler
 
+[![CI](https://github.com/simochee/backlog-unfurler/actions/workflows/ci.yml/badge.svg?branch=main)](https://github.com/simochee/backlog-unfurler/actions/workflows/ci.yml)
+
 A browser extension that automatically unfurls Backlog issue URLs.