refactor: auto-generate language configuration (#1584)

Refactor the monolithic `lvim.lang` design into a more modular approach.

IMPORTANT: run `:LvimUpdate` in order to generate the new ftplugin template files.

lua/core/log.lua

@@ -8,6 +8,7 @@ function Log:add_entry(msg, level)
   if self.__handle then
     -- plenary uses lower-case log levels
     self.__handle[level:lower()](msg)
+    return
   end
   local status_ok, plenary = pcall(require, "plenary")
   if status_ok then