Extends license description

Author: radiospiel

ext/json/ext/vendor/fpconv/README.md

@@ -1,3 +1,5 @@
 The contents of this directory is extracted from https://github.com/night-shift/fpconv
 
-It is licensed under the provisions of the Boost Software License - Version 1.0 - August 17th, 2003. See the ./license file for details.
+It is licensed under the provisions of the Boost Software License - Version 1.0 - August 17th, 2003. See the ./license file for details.
+
+It was slightly modified to append ".0" to plain floats, for use with the https://github.com/ruby/json package.