Added contributing guidelines.

See: https://github.com/blog/1184-contributing-guidelines

CONTRIBUTING.md

@@ -0,0 +1,60 @@
+How to contribute to Dolibarr
+=============================
+
+Bug reports and feature requests
+--------------------------------
+Issues are tracked at [Doliforge](https://doliforge.org/projects/dolibarr)
+
+*You need to create an account before being able to use the "Bugs & Tasks" feature.*
+
+1. Use the search engine to check if nobody's already reported your problem.
+2. Choose the right section. (Bugs or Task and Feature Request).
+3. Report with as much detail as possible (Use screenshots or even screencasts whenever possible).
+
+Code
+----
+1. Fork the [GitHub repository](https://github.com/Dolibarr/dolibarr).
+2. Clone your fork.
+3. Commit and push your changes.
+4. Make a pull request.
+
+### General rules
+Please don't edit the ChangeLog file. A project manager will update it from your commit messages.
+
+### Commits
+Use clear commit messages with the following structure:
+
+<pre>
+KEYWORD Short description
+
+Long description (Can span accross multiple lines).
+</pre>
+
+Where KEYWORD is one of:
+
+- void: don't put a keyword if the commit is not introducing feature or closing a bug.
+- NEW: for new features (May be followed by the task number i.e: #123)
+- FIXED: for bug fixes (May be followed by the bug number i.e: #456)
+
+### Resources
+[Developer documentation](http://wiki.dolibarr.org/index.php/Developer_documentation)
+
+Translations
+------------
+en_US and delta languages (i.e: fr_XX) are maintained in the repository. See Code section above.
+
+All other translations are managed online at [Transifex](https://www.transifex.com/projects/p/dolibarr).
+
+Join an existing translation team or create your own and translate into the interface.
+
+Your translations will be available in the next major release.
+
+### Resources
+[Translator documentation](http://wiki.dolibarr.org/index.php/Developer_documentation)
+
+Documentation
+-------------
+The project's documentation is maintained on the [Wiki](http://wiki.dolibarr.org/index.php).
+
+*You need to create an account before being able to edit.*
+