ci) add gitea actions and refresh readme

.gitea/workflows/pr-checks.yml

@@ -0,0 +1,32 @@
+name: PR Checks
+
+on:
+  pull_request:
+
+jobs:
+  lint-test-and-docker-build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Setup Bun
+        uses: oven-sh/setup-bun@v2
+        with:
+          bun-version: '1.3.3'
+
+      - name: Install dependencies
+        run: bun install --frozen-lockfile
+
+      - name: Lint
+        run: bun run lint
+
+      - name: Unit tests
+        run: bun run test
+
+      - name: Build app
+        run: bun run build
+
+      - name: Build Docker image
+        run: docker build --file Dockerfile --tag trips:pr-${{ github.sha }} .