Add IOMAP=all to README

README.md

@@ -30,11 +30,11 @@ Build with:
 
     msbuild
 
-# Running:
+## Running:
 
-You can run with:
+You can run with (note the MONO_IOMAP=all to make it treat files case insensitive):
 
-    ERA=/path/to/eragame mono NTERA/bin/Debug/NTERA.exe
+    ERA=/path/to/eragame MONO_IOMAP=all mono NTERA/bin/Debug/NTERA.exe
 
 ## Development