Added some infos on how to build the documentation.

COMPILE

@@ -77,3 +77,11 @@ for 64 bits systems
 VISUAL C++ USERS
 .........................................................
 Open squirrel.dsw from the root project directory and build(dho!)
+
+
+DOCUMENTATION GENERATION
+.........................................................
+To be able to compile the documentation, make sure that you have Python
+installed and the packages sphinx and sphinx_rtd_theme. Browse into doc/
+and use either the Makefile for GCC-based platforms or make.bat for
+Windows platforms.