Developer Guidelines, adding style

CONTRIBUTING.md

-# Contributing
-
-## Code contribution
-
-We use Git to share and merge our code.
-
-## Style
-
-We are using the common Haskell Style:
-https://github.com/tibbe/haskell-style-guide/blob/master/haskell-style.md
-
-## Code Of Conduct
-
-Be constructive as sharing our code of conduct
-
-## Chat with us
-
-We are on IRC:  [irc.oftc.net, channel #gargantext](ircs://irc.oftc.net:6697/#gargantext)
-
-You can join via Matrix, just search for: #_oftc_#gargantext:matrix.org
-
-You can also join via XMPP: <xmpp://#gargantext%irc.oftc.net@irc.jabberfr.org?join>

DEVELOPER_GUIDELINES.md

@@ -39,6 +39,7 @@ all developers about how to:
 
 The rest of the document try to answer all those questions.
 
+
 ## Glossary
 
 - GIT: _Git_ is a distributed version control system
@@ -57,7 +58,25 @@ The rest of the document try to answer all those questions.
 
 The following is a non-exhaustive list of the development guidelines.
 
-### Main working Branches
+### Style
+
+When we code, we are using the [common Haskell Style guide](https://github.com/tibbe/haskell-style-guide/blob/master/haskell-style.md).
+
+### Code Of Conduct
+
+Please be constructive as sharing our [code of conduct](https://gitlab.iscpif.fr/gargantext/main/blob/master/CODE_OF_CONDUCT.md).
+
+### Chat with us !
+
+We are on IRC:  [irc.oftc.net, channel #gargantext](ircs://irc.oftc.net:6697/#gargantext)
+
+You can join via Matrix, just search for: #_oftc_#gargantext:matrix.org
+
+You can also join via XMPP: <xmpp://#gargantext%irc.oftc.net@irc.jabberfr.org?join>
+
+## Git Collaboration Guidelines
+
+### Git Main working Branches
 
 3 main branches are used in the distributed version control system (Git) of GarganText:
 - _dev_ branch for latest development