What is the wisdom of storing the following reference files in the user's directory?
Might I have done something when installing XCode for them to go to ~/Library instead of, say, /Library ?
1.8G ~/Library/Developer/Shared/Documentation/DocSets/
0.3G ~/Library/Developer/Shared/Documentation/DocSets/com.apple.ADC_Reference_Library.DeveloperTools.4_3.docset
1.0G ~/Library/Developer/Shared/Documentation/DocSets/com.apple.adc.documentation.AppleLion.CoreReference.docset
0.5G ~/Library/Developer/Shared/Documentation/DocSets/com.apple.adc.documentation.AppleiOS5_1.iOSLibrary.docset
Pseudo-solution
Aside from the wisdom, if any, the solution suggested by Anne Onymous below works.
sudo mkdir -p /Library/Developer/Shared/Documentation
sudo mv ~/Library/Developer/Shared/Documentation/DocSets /Library/Developer/Shared/Documentation/
ln -s /Library/Developer/Shared/Documentation/DocSets ~/Library/Developer/Shared/Documentation/DocSets
Doing so will significantly reduce the number of files in your home directory:
ls -lR ~/Library/Developer/Shared/Documentation/DocSets | wc
302148 1881376 20167032