manpage: fix typo

DOCS/man/en/lua.rst

@@ -3,7 +3,7 @@ LUA SCRIPTING
 
 mpv can load Lua scripts. These scripts can be used to control mpv in a similar
 way to slave mode. mpv provides the builtin module ``mp`` (can be loaded
-with ``require 'mpv'``), which provides functions to send commands to the
+with ``require 'mp'``), which provides functions to send commands to the
 mpv core and to retrieve information about playback state, user settings,
 file information, and so on.