Update convertLibsvm README.
Update convertLibsvm README.

nemesiscodex/mockingbird,nemesiscodex/mockingbird,lazywei/mockingbird,lazywei/mockingbird,lazywei/mockingbird,nemesiscodex/mockingbird,lazywei/mockingbird,lazywei/mockingbird,lazywei/mockingbird,nemesiscodex/mockingbird,lazywei/mockingbird,nemesiscodex/mockingbird,nemesiscodex/mockingbird,nemesiscodex/mockingbird,nemesiscodex/mockingbird,lazywei/mockingbird,nemesiscodex/mockingbird,lazywei/mockingbird