Added build target description to howtobuild

how-to-build.txt

@@ -3,6 +3,17 @@ PSake is a powershell based build tool and is packed with the source (psake.ps1)
 
 To build simply execute psake.ps1.
 
+Possible build targets:
+* Clean = Removes all build artefacts
+* Build = Builds the main ElmsConnector library
+* Test = Builds testproject and runs Unit tests using xUnit
+* Merge = Merges Castle assemblies into ElmsConnector.dll
+* Release = (Default) Executes Build, Test, Merge and creates a release zip.
+
+To run another build targert simply run:
+PS> .\psake .\default.ps1 <target>
+
+
 Note:
 You may need to execute the following command before being able to execute the script:
 Set-ExecutionPolicy remotesigned