Document browser branch

Author: chenglou

README.md

@@ -1,6 +1,8 @@
 # ReScript Project Template
 
-The only official ReScript starter template.
+The only official ReScript starter template. Clone this repo to get started.
+
+This is the branch where you can use your output code in NodeJS. To use your output in the browser, do `git checkout -b browser origin/browser` to switch to the `browser` branch.
 
 ## Installation