Add meta

Meta/api/InCombatLockdown.lua

@@ -0,0 +1,5 @@
+---@diagnostic disable: missing-return, lowercase-global
+
+---@return 1nil inLockdown 
+---Returns whether the user interface is protected due to combat. Non-Blizzard code is allowed to perform certain UI actions (such as changing secure template attributes or moving/showing/hiding secure frames) only if the player is not in combat; this function can be used to determine whether such actions are currently available.
+function InCombatLockdown() end