Recover original readme and add dev container section

readme.rst

@@ -9,10 +9,12 @@ Installation
 
 ::
 
-    sudo apt-get install npm nodejs-legacy
+    sudo apt-get install npm nodejs-legacy ruby
     git clone https://github.com/titilambert/adagios-frontend.git
     cd adagios-frontend
     npm install
+    npm install grunt-cli
+    gem install sass
 
 
 Dev
@@ -22,9 +24,14 @@ To watch for sass files change and auto-refresh css run :
 
 ::
 
-    npm install grunt-cli
     grunt
 
+To compile css files run :
+
+::
+
+    grunt sass
+
 If you wish to develop in a docker container, here is how to proceed (assuming
 you already have docker installed) :
 
@@ -35,6 +42,7 @@ you already have docker installed) :
     make run
     curl http://localhost/app
 
+
 Coding style
 ===========
 
@@ -65,3 +73,27 @@ Launch
 
 
 Now, go on http://127.0.0.1:8000
+
+Contributing
+============
+
+To contribute to this project, please fork the repo. Then do your commits (branch as you will)
+and then open a pull-request to this repo's master branch.
+
+::
+
+    <fork this repo on github>
+    git clone your-repo/adagios-frontend
+    git checkout -b dev-new-feature-xx
+    git commit ...
+    git push origin dev-new-feature-xx
+    <You can now open your pull-request to this repo's master>
+
+Good practices before opening a pull request:
+
+    - Run tests with `npm test`
+    - Lint your .js files with `grunt jslint`
+    - Make sure your directives are prefixed with `adg`
+    - Make sure your controllers are suffixed with `Ctrl`
+    - Resolve merge conflicts locally
+