Improve the getting started instructions in the GC docs
Improve the getting started instructions in the GC docs

This is still gcroot vs gc.statepoint agnostic.  I'm just trying to clarify the general documentation at this point.



git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@230393 91177308-0d34-0410-b5e6-96231b3b80d8

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