Update Readme

Author: tomlokhorst

README.md

@@ -1,16 +1,19 @@
 <img src="https://cloud.githubusercontent.com/assets/75655/10141830/f92646ca-660e-11e5-8e1e-40c90482ead0.png" width="175" alt="Xcode.swift">
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-Reading the the Xcode pbxproj file format, from Swift!
+Reading _and writing_ the the Xcode pbxproj file format, from Swift!
+
+The main goal of this project is to generate `project.pbxproj` files in the legacy OpenStep format used by Xcode. Using this, a project file can be modified without changing it to XML format and causing a huge git diff.
 
 Currently, this project is mostly used to support [R.swift](https://github.com/mac-cain13/R.swift).
 
 
 Releases
 --------
 
- - **0.1.0** - 2015-09-28 - Initial public release
+ - 0.2.1 - 2015-12-30 - Add missing PBXProxyReference class
  - **0.2.0** - 2015-10-29 - Adds serialization support
+ - **0.1.0** - 2015-09-28 - Initial public release
 
 
 Licence & Credits