Add .luacheckrc.

This change removes 8 warnings from debug.txt every time server starts.
2018-06-12 11:17:25: WARNING[Main]: Deprecated use of colon notation when calling method `register_hook` at @/minetest/mods/irc_commands/init.lua:14
2018-06-12 11:17:25: WARNING[Main]: Deprecated use of colon notation when calling method `register_hook` at @/minetest/mods/irc_commands/init.lua:23
2018-06-12 11:17:25: WARNING[Main]: Deprecated use of colon notation when calling method `register_hook` at @/minetest/mods/irc_commands/init.lua:27
2018-06-12 11:17:25: WARNING[Main]: Deprecated use of colon notation when calling method `register_hook` at @/minetest/mods/irc_commands/init.lua:31
2018-06-12 11:17:25: WARNING[Main]: Deprecated use of colon notation when calling method `register_bot_command` at @/minetest/mods/irc_commands/init.lua:35
2018-06-12 11:17:25: WARNING[Main]: Deprecated use of colon notation when calling method `register_bot_command` at @/minetest/mods/irc_commands/init.lua:77
2018-06-12 11:17:25: WARNING[Main]: Deprecated use of colon notation when calling method `register_bot_command` at @/minetest/mods/irc_commands/init.lua:91
2018-06-12 11:17:25: WARNING[Main]: Deprecated use of colon notation when calling method `register_bot_command` at @/minetest/mods/irc_commands/init.lua:118

.luacheckrc

@@ -0,0 +1,8 @@
+
+unused_args = false
+allow_defined_top = true
+
+read_globals = {
+	"minetest",
+	"irc",
+}

init.lua

@@ -2,7 +2,7 @@
 local irc_users = {}
 
 local old_chat_send_player = minetest.chat_send_player
-minetest.chat_send_player = function(name, message)
+minetest.chat_send_player = function(name, message) -- luacheck: ignore
 	for nick, loggedInAs in pairs(irc_users) do
 		if name == loggedInAs and not minetest.get_player_by_name(name) then
 			irc:say(nick, message)
@@ -138,4 +138,3 @@ irc.register_bot_command("say", {
 	end
 })
 
-minetest.log("action", "[irc_commands] loaded.")

mod.conf

@@ -0,0 +1 @@
+name = irc_commands