[install-guide] Added admonition that GRUB2 cannot be installed to a partition

[Jack Reed]

commit c838ce06d5e103ad47d295d9791001b3c1e0652c
Author: Jack Reed <jreed at redhat.com>
Date:   Tue Jan 15 10:52:19 2013 +1000

    Added admonition that GRUB2 cannot be installed to a partition

 en-US/Grub.xml |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)
---
diff --git a/en-US/Grub.xml b/en-US/Grub.xml
index 74a1a4c..aca13ac 100644
--- a/en-US/Grub.xml
+++ b/en-US/Grub.xml
@@ -335,6 +335,13 @@
 		 <para>
 			The next time the system boots, the GRUB graphical boot loader menu appears before the kernel loads into memory.
 		</para>
+		
+		<important>
+		  <para>
+			Beginning in Fedora 18, GRUB2 can no longer be installed to a partition.
+		  </para>
+		</important>
+		
 		 <!-- <important>
 			<title>Important — GRUB and RAID</title>
 			 <indexterm significance="normal">