Remove the data/csur/README.md file.

This information has been added to the main README.md file, so is
now redundant.

data/csur/README.md

-# ConScript Unicode Registry (CSUR)
-
-This folder contains data from the [CSUR](http://www.evertype.com/standards/csur/)
-in a form that is parsable by Unicode Character Database tools.
-
-Currently, the following table data has been defined:
-  *  [Klingon](http://www.evertype.com/standards/csur/klingon.html) [F8D0-F8FF]