add developers section

git-svn-id: https://redmine.imt-atlantique.fr/svn/xaal/code/Python/trunk@1083 b32b6428-25c9-4566-ad07-03861ab6144f

apps/frontend/polymer/xaal-webui-polymer/README.md

@@ -12,7 +12,9 @@ At least, the following devices are mandatory:
     * "xaal-restapi"
     * One xAAL device :-)
 
-You need to also install xaal-webcomponents-polymer
+Bower is required to manage the frontend dependancies.
+
+You need to also install xaal-webcomponents-polymer with bower
 
 ## Getting started
 
@@ -21,6 +23,14 @@ Python 2.x:
 python -m SimpleHTTPServer
 ```
 
+## For developpers 
+
+An other repository has been used to develop all xaal webcomponents (see in the
+svn).
+So if you find bugs related to xaal webcomponents, the source code is in a
+separate repo.
+
+
 ## TODO list
 
 - [x] Add polymer template  with polymer starter kit