Update README.md (#912)

Add PR naming convention

Author: m30m

README.md

@@ -45,6 +45,16 @@ and examples for your blockchain runtime in the `target_chains` directory.
 
 ## Development
 
+### Pull requests
+
+Use the following format for naming the pull requests:
+
+[component] PR description
+
+For example:
+
+[hermes] Add storage tests
+
 ### Releases
 
 The repository has a CI workflow that will release javascript packages whose version number has changed.