Add note that keywords are case insensitive

Signed-off-by: Andi Kleen <ak@linux.intel.com>
diff --git a/mce-inject.8 b/mce-inject.8
index 4bee52f..9e43a94 100644
--- a/mce-inject.8
+++ b/mce-inject.8
@@ -84,6 +84,7 @@
 For all missing fields reasonable default values are filled in
 (hopefully)
 Comments start with # until the end of the line
+The keywords are case-insensitive.
 .SH REQUIREMENTS
 mce-inject to run as root. /dev/mcelog has to exist. The kernels needs
 to have machine check injection (