Improve the readme

- Correct some style problems
- Add syntax highlighting
- Explain version management
- Add contact infos

Author: jecisc

README.md

@@ -1,29 +1,51 @@
 # MaterialColors
 
-####Linux/OSX builds
+#### Linux/OSX builds
 Master: [![Build Status](https://travis-ci.org/DuneSt/MaterialColors.svg?branch=master)](https://travis-ci.org/DuneSt/MaterialColors)
 
-####Windows builds
+#### Windows builds
 Master: [![Build status](https://ci.appveyor.com/api/projects/status/3dn6m0k68jjenk6v/branch/master?svg=true)](https://ci.appveyor.com/project/jecisc/materialcolors/branch/master) | Latest commit: [![Build status](https://ci.appveyor.com/api/projects/status/3dn6m0k68jjenk6v?svg=true)](https://ci.appveyor.com/project/jecisc/materialcolors) 
 
 A project to extends Pharo colors's classes with the Material Design recommandations
 
+
+# Documentation
+
+## Version management 
+
+This project use semantic versionning to define the releases. This mean that each stable release of the project will get associate a version number of the form `vX.Y.Z`. 
+
+- **X** define the major version number
+- **Y** define the minor version number 
+- **Z** define the patch version number
+
+When a release contains only bug fixes, the patch number increase. When the release contains new features backward compatibles, the minor version increase. When the release contains breaking changes, the major version increase. 
+
+Thus, it should be safe to depend on a fixed major version and moving minor version of this project.
+
 ## Install MaterialColors
 
 To install MaterialColors on your Pharo image you can just execute the following script: 
 
+```Smalltalk
     Metacello new
     	githubUser: 'DuneSt' project: 'MaterialColors' commitish: 'master' path: 'src';
     	baseline: 'MaterialColors';
     	onWarningLog;
     	load
+```
 
 To add MaterialColors to your baseline just add this: 
 
+```Smalltalk
     spec
     	baseline: 'MaterialColors'
     	with: [ spec repository: 'github://DuneSt/MaterialColors:master/src' ]
+```
     	
-Note that you can replace the #master by another branch as #development or a tag as #v1.0.0.
+Note that you can replace the #master by another branch as #development or a tag as #v1.0.0 or #v1.0.? or #v1.x.x .
+
 
+## Contact
 
+If you have any question or problem do not hesitate to open an issue or contact cyril (a) ferlicot.me