feat: add type annotations for plenary.path

Author: delphinus

lua/plenary/init.lua

@@ -1,5 +1,6 @@
 -- Lazy load everything into plenary.
 ---@class Plenary
+---@field path PlenaryPath
 local plenary = setmetatable({}, {
   __index = function(t, k)
     local ok, val = pcall(require, string.format("plenary.%s", k))