Update readme for conflicts

Author: amanda11

README.md

@@ -39,6 +39,12 @@ then you need to bootstrap the micromodules
 $ lerna bootstrap
 ```
 
+to avoid conflicts on node_modules, delete those generated by lerna:
+
+```shell
+$ rm -rf apps/st2-workflows/node_modules/
+```
+
 and finally run build system to fetch the font, compile css and so on
 
 ```shell