updated the recommended config to use an rc file

Author: travi

README.md

@@ -32,7 +32,7 @@ $ npm install commitlint-config-travi -D
 ### Define the config for your project
 
 ```sh
-$ echo "module.exports = {extends: ['travi']};" > commitlint.config.js
+$ echo "module.exports = {extends: ['travi']};" > .commitlintrc.js
 ```
 
 ### Define the npm script for [husky](https://github.com/typicode/husky)