chore: add misc file

lua/Trans/backend/init.lua

@@ -0,0 +1,13 @@
+local M = {}
+
+
+M.__index = function(tbl, k)
+    local res, engine = pcall(require, 'Trans.backend.' .. k)
+    assert(res, [[Can't Found Engine:]] .. k)
+
+    tbl[k] = engine
+    return engine
+end
+
+
+return setmetatable(M, M)