Updating supported search types and parameters in README.
Updating supported search types and parameters in README.

mschmele/Common-Metadata-Repository,mschmele/Common-Metadata-Repository,nasa/Common-Metadata-Repository,mschmele/Common-Metadata-Repository,nasa/Common-Metadata-Repository,nasa/Common-Metadata-Repository,nasa/Common-Metadata-Repository,nasa/Common-Metadata-Repository,nasa/Common-Metadata-Repository,mschmele/Common-Metadata-Repository