#34 - 깃헙 gradle check 액션 추가

pr을 작성할 때 깃헙 체크 액션이 자동으로 실행되어
`./gradlew build` 빌드 명령어를 실행하게 한다.
이것으로 pr 작성할 때마다 빌드 + 테스트를 자동화할 수 있게 된다.

.github/workflows/gradle.yml

@@ -0,0 +1,67 @@
+# This workflow uses actions that are not certified by GitHub.
+# They are provided by a third-party and are governed by
+# separate terms of service, privacy policy, and support
+# documentation.
+# This workflow will build a Java project with Gradle and cache/restore any dependencies to improve the workflow execution time
+# For more information see: https://docs.github.com/en/actions/automating-builds-and-tests/building-and-testing-java-with-gradle
+
+name: Java CI with Gradle
+
+on:
+  # push:
+  #   branches: [ "main" ]
+  pull_request:
+    branches: [ "main" ]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+
+    steps:
+    - uses: actions/checkout@v4
+    - name: Set up JDK 21
+      uses: actions/setup-java@v4
+      with:
+        java-version: '21'
+        distribution: 'temurin'
+
+    # Configure Gradle for optimal use in GitHub Actions, including caching of downloaded dependencies.
+    # See: https://github.com/gradle/actions/blob/main/setup-gradle/README.md
+    - name: Setup Gradle
+      uses: gradle/actions/setup-gradle@dbbdc275be76ac10734476cc723d82dfe7ec6eda # v3.4.2
+
+    - name: Build with Gradle Wrapper
+      run: ./gradlew build
+
+    # NOTE: The Gradle Wrapper is the default and recommended way to run Gradle (https://docs.gradle.org/current/userguide/gradle_wrapper.html).
+    # If your project does not have the Gradle Wrapper configured, you can use the following configuration to run Gradle with a specified version.
+    #
+    # - name: Setup Gradle
+    #   uses: gradle/actions/setup-gradle@dbbdc275be76ac10734476cc723d82dfe7ec6eda # v3.4.2
+    #   with:
+    #     gradle-version: '8.5'
+    #
+    # - name: Build with Gradle 8.5
+    #   run: gradle build
+
+  dependency-submission:
+
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+
+    steps:
+    - uses: actions/checkout@v4
+    - name: Set up JDK 21
+      uses: actions/setup-java@v4
+      with:
+        java-version: '21'
+        distribution: 'temurin'
+
+    # Generates and submits a dependency graph, enabling Dependabot Alerts for all project dependencies.
+    # See: https://github.com/gradle/actions/blob/main/dependency-submission/README.md
+    - name: Generate and submit dependency graph
+      uses: gradle/actions/dependency-submission@dbbdc275be76ac10734476cc723d82dfe7ec6eda # v3.4.2