Update README.md

Author: Antoine Kevin

README.md

@@ -260,3 +260,20 @@ You can grab the next page of results using the client:
 ```php
 $client->nextPage($response["pages"]);
 ```
+
+
+## Pull Requests
+
+- **Add tests!** Your patch won't be accepted if it doesn't have tests.
+
+- **Document any change in behaviour**. Make sure the README and any other
+  relevant documentation are kept up-to-date.
+
+- **Create topic branches**. Don't ask us to pull from your master branch.
+
+- **One pull request per feature**. If you want to do more than one thing, send
+  multiple pull requests.
+
+- **Send coherent history**. Make sure each individual commit in your pull
+  request is meaningful. If you had to make multiple intermediate commits while
+  developing, please squash them before sending them to us.