Minor - add info to contribute.md

CONTRIBUTING.md

@@ -3,7 +3,25 @@ Contributing
 
 Chamilo LMS is a free software, community-driven project.
 
-If you'd like to contribute, please read the following document:
+Chamilo LMS is an LAMP-based e-learning web platform that focuses on providing an easy-to-use
+environment for teachers to improve both the quality and availability of their
+educational material, and on providing students with an awesome learning platform.
+
+We are a relatively small development team and greatly welcome any contribution
+from the outside world, although we will thoroughly review them before integration,
+to make sure they do not introduce security vulnerabilities or degrade the ease
+of use of the platform.
+
+The 1.10.x (that you're currently looking at) is a development branch for the 
+1.10.0 release, that we hope to be releasing around mid-2015. It is a 
+transitional version that partially uses a series of Symfony 2 modules but relies
+heavily on Composer to manage the dependencies towards common libraries. Version 
+2.0 has already been worked a lot on, and has served as an inspiration for 1.10.0,
+but due to the huge success of the 1.9.x series, we decided to take a transitional
+step towards 2.0 to ensure a smooth migration of all our user base to the newer
+version (to be released sometime in 2016).
+
+If you'd like to contribute to this project, please read the following document:
 
 * [Coding conventions][1]: The main conventions document
 * [PSR-1][2]: PSR-1 are standard conventions rules we use as a base (conversion of old code still in progress)