Update README.md

Author: raph-amiard

README.md

@@ -8,7 +8,10 @@ Installation
 
 You need to have node.js installed before anything.
 
-Clone the repository in your sublime "Packages" directory. You need to clone with the --recursive option, or to put the typescript *source* into the lib/typescript directory.
+Clone the repository in your sublime "Packages" directory. 
+You need to clone with the --recursive option, or to put the typescript *source* into the lib/typescript directory.
+You also need to ensure that the node executable is on your path, or that the "node_path" key is set somewhere in a
+typescript.sublime-settings settings file that sublime text can reach.
 
 ~~~sh
 git clone https://github.com/raph-amiard/sublime-typescript --recursive