M README.md → README.md

@@ -9,7 +9,7 @@ _NimHTTPd_ is a minimal web server that can be used to serve static files.
 
 ## Usage
 
-**nimhttpd** **[** **-p:**_port_ **-t:**_title_ **-a:**_address_ **]** **[** _directory_ **]**
+**nimhttpd** **[** **-6** **-p:**_port_ **-t:**_title_ **-a:**_address_ **]** **[** _directory_ **]**
 
 Where:
 
@@ -18,3 +18,4 @@ - _port_ is the port to listen to (default: 1337). If the specified port is
   unavailable, the number will be incremented until an available port is found.
 - _address_ is the address to bind to (default: 0.0.0.0).
 - _title_ is the title to use when listing the contents of a directory.
+- _-6_ enables IPv6 support