Add composite action

.github/workflows/test-action.yml

@@ -0,0 +1,14 @@
+name: Test action
+
+on:
+  pull_request:
+    branches: [trunk]
+
+jobs:
+  runs-on: ubuntu-latest
+  steps:
+    - name: Install ghelper
+      uses: 3lvia/ghelper@feat/action
+
+    - name: Run ghelper
+      run: ghelper exec -x 'cat LICENSE' 3lvia/ghelper

README.md

@@ -112,3 +112,22 @@ Examples:
 3. Run a custom shell script on the repositories listed in 'repositories.txt', and don't clean up the working directory:
    ghelper exec -x 'sh ./my-script.sh' -w /home/user/my-working-dir repositories.txt
 ```
+
+### Usage in GitHub Actions
+
+```yaml
+name: ghelper
+
+on:
+  pull_request:
+    branches: [trunk]
+
+jobs:
+  runs-on: ubuntu-latest
+  steps:
+    - name: Install ghelper
+      uses: 3lvia/ghelper@trunk
+
+    - name: Run ghelper
+      run: ghelper exec -x 'cat LICENSE' 3lvia/ghelper
+```

action.yml

@@ -0,0 +1,18 @@
+name: 'Install ghelper'
+description: 'Install ghelper to use in your workflow.'
+
+runs:
+  using: 'composite'
+  steps:
+    - name: Checkout ghelper repository
+      uses: actions/checkout@v4
+      with:
+        repository: '3lvia/ghelper'
+        path: '/tmp/ghelper'
+
+    - name: Install ghelper
+      shell: bash
+      run: |
+        cp /tmp/ghelper/ghelper /usr/local/bin/ghelper
+        chmod +x /usr/local/bin/ghelper
+        rm -rf /tmp/ghelper