Documentation: add Ramoops usage description

Add a documentation file describing the usage of Ramoops

Signed-off-by: Sergiu Iordache <sergiu@chromium.org>
Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/Documentation/00-INDEX b/Documentation/00-INDEX
index 1f89424..65bbd26 100644
--- a/Documentation/00-INDEX
+++ b/Documentation/00-INDEX
@@ -272,6 +272,8 @@
 	- how to get printk format specifiers right
 prio_tree.txt
 	- info on radix-priority-search-tree use for indexing vmas.
+ramoops.txt
+	- documentation of the ramoops oops/panic logging module.
 rbtree.txt
 	- info on what red-black trees are and what they are for.
 robust-futex-ABI.txt