[plt-scheme] a documentation request

My tech support people humbly request that for the next release, could a 
readme describing the places where files are placed by a DrScheme 
installation please be added? The mode of operation here seems to be to 
build on one machine and then copy to others. Under Mac OS X Server, 
they didn't copy over the material in /Library/Frameworks, and the 
DrScheme application simply wouldn't launch during our first lab 
yesterday. (Fortunately, we had an earlier version correctly installed 
by erstwhile support people, so we used that.) Thanks. --PR