updated readme

README.md

@@ -35,7 +35,7 @@ You can use the following flags to search using different parameters:
 - `-j/--device_category` OPTIONAL, search for requests from certain devices (pc", "smartphone", "mobilephone", "appliance", "crawler", "misc", "unknown")
 - `-w/--su` OPTIONAL, find lines that are unique by session for a given log selection
 - `-c/--cm` OPTIONAL, read file line-by-line to use almost no memory (cannot be used with analytical tools)
-
+- `-y/--uniqueby` OPTIONAL, regex to use something other than ip for ip related searches
 #### Example Run: `ngxav -f access.log -a`
 
 Output: