Added License.

Author: WaveFunctionP

README.md

@@ -2,3 +2,5 @@ ForScience
 ==========
 
 A science enhancement plugin for Kerbal Space Program.
+
+<a rel="license" href="http://creativecommons.org/licenses/by-sa/4.0/"><img alt="Creative Commons License" style="border-width:0" src="http://i.creativecommons.org/l/by-sa/4.0/88x31.png" /></a><br />This work is licensed under a <a rel="license" href="http://creativecommons.org/licenses/by-sa/4.0/">Creative Commons Attribution-ShareAlike 4.0 International License</a>.