Add notes for releasing chrome launcher

CONTRIBUTING.md

@@ -97,7 +97,7 @@ echo "Upload the package zip to CWS dev dashboard"
 
 echo "Verify the npm package won't include unncessary files"
 yarn global add irish-pub pkgfiles
-irish-pub; pkgfiles;  
+irish-pub; pkgfiles;
 
 echo "ship it"
 npm publish
@@ -110,6 +110,17 @@ echo "Generate the release notes, and update the release page"
 echo "Inform various peoples"
 ```
 
+### Releasing chrome launcher.
+
+```sh
+cd chrome-launcher
+echo "build the launcher source code"
+yarn build
+echo "run npm version [<newversion> | major | minor | patch | premajor | preminor | prepatch | prerelease | from-git]"
+echo "commit the change as a version bump"
+npm publish
+```
+
 ### Canary release
 
 ```sh