check project code style. add .luacheckrc (#7)

druid/settings.lua

@@ -6,7 +6,7 @@ M.button = {
 	IS_HOVER = true,
 	IS_HOLD = true,
 	BTN_SOUND = "click",
-	BTN_SOUND_DISABLED = "button_click_disabled",
+	BTN_SOUND_DISABLED = "click_disabled",
 	HOVER_SCALE = vmath.vector3(-0.025, -0.025, 1),
 	HOVER_TIME = 0.05,
 	SCALE_CHANGE = vmath.vector3(-0.05, - 0.05, 1),
@@ -24,6 +24,7 @@ function M.play_sound(name)
   -- override to play sound with name
 end
 
+
 function M.log(...)
 	if M.is_debug then
 		print("[Druid]: ", ...)
@@ -31,5 +32,4 @@ function M.log(...)
 end
 
 
-
 return M