Add user-guide & sample story for managed types in design doc
Add user-guide & sample story for managed types in design doc

This change is done as a preliminary to splitting gradle/langos#8.
Design spec for this story contained some details about user-guide and
samples content so instead of just removing theses details this commit
moves them into a distinct story: gradle/langos#20

Issue: gradle/langos#20

blindpirate/gradle,gstevey/gradle,blindpirate/gradle,blindpirate/gradle,robinverduijn/gradle,robinverduijn/gradle,lsmaira/gradle,gstevey/gradle,lsmaira/gradle,lsmaira/gradle,gstevey/gradle,blindpirate/gradle,gradle/gradle,robinverduijn/gradle,lsmaira/gradle,robinverduijn/gradle,lsmaira/gradle,gstevey/gradle,gstevey/gradle,gstevey/gradle,gstevey/gradle,gradle/gradle,lsmaira/gradle,blindpirate/gradle,blindpirate/gradle,gradle/gradle,blindpirate/gradle,robinverduijn/gradle,gstevey/gradle,gradle/gradle,blindpirate/gradle,robinverduijn/gradle,gradle/gradle,lsmaira/gradle,robinverduijn/gradle,gradle/gradle,robinverduijn/gradle,robinverduijn/gradle,robinverduijn/gradle,gradle/gradle,lsmaira/gradle,gradle/gradle,lsmaira/gradle,robinverduijn/gradle,blindpirate/gradle,lsmaira/gradle,gradle/gradle,blindpirate/gradle,gstevey/gradle,gradle/gradle