Add comment about compiling.

drvinceknight · drvinceknight · commit f667fcbb1a89 · 2017-08-23T07:52:24.000+01:00
diff --git a/README.rst b/README.rst
@@ -3,13 +3,16 @@ Overview
 ========
 
 
-Python wrapper for strategies originally written in Fortran
+Python wrapper for strategies originally written in Fortran.
 
 * Free software: MIT license
 
 Installation
 ============
 
+To use this library the original Fortran code must be compiled:
+https://github.com/Axelrod-Python/TourExec.
+
 ::
 
     pip install axelrod-fortran
