Added text about versionning.

Author: juliendelplanque

README.md

@@ -13,6 +13,18 @@ Metacello new
 
 Once Python3Generator is installed in your image, you need to configure [Python3Generator](https://github.com/juliendelplanque/Python3Generator) to use the Python interpreter you prefer. My advise is to use the FFI interpreter using: `P3GInterpreter useFFIInterpreter`. If your `python3` binary is located in a standard path in your file system, it should be fine, else you can manually set the path to `python3` binary using for example: `P3GInterpreter current pathToPython: '/usr/bin/python3'`.
 
+## 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.
+
 ## Examples
 ### Getting os information in `/tmp/os.json` file
 ```