add a consistent set of text about X11

1993/cmills/README.md

@@ -10,7 +10,7 @@ section below to run the original (the bug also exists here).
 ```
 
 NOTE: this entry requires the `X11/Xlib.h` header file and the X11 library to
-compile. If you don't have the X11 installed see the
+compile.  For more information see the
 FAQ on "[X11](../../faq.html#X11)".
 
 To configure how many microseconds to sleep before updates try: