add github action

Author: alexcheng1982

.github/FUNDING.yml

@@ -0,0 +1,2 @@
+ko_fi: alexcheng1982
+github: alexcheng1982

.github/workflows/build.yaml

@@ -0,0 +1,22 @@
+name: build
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v4
+      - name: Set up JDK
+        uses: actions/setup-java@v3
+        with:
+          java-version: "21"
+          distribution: "temurin"
+          cache: maven
+      - name: Build with Maven
+        run: mvn --batch-mode --update-snapshots package

README.md

@@ -5,9 +5,10 @@ data: [Netflix data](https://github.com/neondatabase/postgres-sample-dbs?tab=rea
 
 How to run:
 
-1. Download test data and import into a Postgres database.
-2. Update database connection in `application.yaml`.
-3. Start the server and
+1. Requires Java 21 to build and run.
+2. Download test data and import into a Postgres database.
+3. Update database connection in `application.yaml`.
+4. Start the server and
    use [Swagger UI](http://localhost:8080/swagger-ui/index.html) to run query.
 
 Sample query: