adds function description stuff

Adds description for figure handle usage.
Adds more usage info in README.
Revert "Adds colormap parameter"

This reverts commit af10260986b90dbf2af00da6f6db275dd11c7ec1.
Revert "Revert "Adds colormap parameter""

This reverts commit 491f61e394a07af314c0bfe5ede6d1621b3b54b9.
cleanup