feat: allow action to work without commitlint config

Author: Dafnik

.github/workflows/ci.yml

@@ -43,4 +43,4 @@ jobs:
         with:
           fetch-depth: 0
 
-      - uses: dafnik/commitlint@main
+      - uses: dafnik/commitlint@main

README.md

@@ -3,6 +3,7 @@
 A simple GitHub action to run [`@commitlint/cli`](https://www.npmjs.com/package/@commitlint/cli) checks.
 
 Following commits are linted based on the action `event_name`.
+
 - `push`: The last commit
   - from `HEAD~1` to `HEAD`
 - `pull_request`
@@ -20,14 +21,17 @@ jobs:
       - name: Checkout Repository
         uses: actions/checkout@v4
         with:
-           fetch-depth: 0
+          fetch-depth: 0
 
       - name: Run commitlint
         uses: dafnik/commitlint@v1
-        with:
+        #with:
           #commitlint_version: 'latest'
 ```
 
+If the action doesn't find a `commitlint.config.js` it's going to install
+[`@commitlint/config-conventional`](https://www.npmjs.com/package/@commitlint/config-conventional) and create a pre-generated `commitlint.config.js`.
+
 <!-- prettier-ignore-start -->
 | Inputs               | Default value | Description                  |
 |----------------------|---------------|------------------------------|
@@ -57,4 +61,4 @@ The scripts and documentation in this project are released under the [MIT Licens
 [release-list]: https://github.com/dafnik/commitlint/releases
 [draft-release]: .github/workflows/draft-release.yml
 [release]: .github/workflows/release.yml
-[release-workflow-runs]: https://github.com/dafnik/commitlint/actions/workflows/release.yml
+[release-workflow-runs]: https://github.com/dafnik/commitlint/actions/workflows/release.yml

action.yml

@@ -25,6 +25,31 @@ runs:
       shell: bash
       run: npm install --global commitlint@${{ inputs.commitlint_version }} @commitlint/config-conventional
 
+    - name: Check if commitlint.config.js exists
+      shell: bash
+      id: check-file
+      run: |
+        if [ -f commitlint.config.js ]; then
+          echo "exists=true" >> $GITHUB_OUTPUT
+        else
+          echo "exists=false" >> $GITHUB_OUTPUT
+        fi
+
+    - name: Installing @commitlint/config-conventional
+      shell: bash
+      if: steps.check-file.outputs.exists == 'false'
+      run: npm install --global @commitlint/config-conventional
+
+    - name: Creating commitlint.config.js
+      shell: bash
+      if: steps.check-file.outputs.exists == 'false'
+      run: |
+        echo "module.exports = { extends: ['@commitlint/config-conventional'] };" > commitlint.config.js
+
+    - name: Verify commitlint.config.js content
+      shell: bash
+      run: cat commitlint.config.js
+
     - name: Validate current commit (last commit) with commitlint
       shell: bash
       if: github.event_name == 'push'