Refactor smartparens default rules

Move them to config/default, but move single-lang-specific ones to their
respective modules.

modules/lang/lua/config.el

@@ -1,5 +1,8 @@
 ;;; lang/lua/config.el -*- lexical-binding: t; -*-
 
+;; sp's default rules are obnoxious, so disable them
+(provide 'smartparens-lua)
+
 (after! lua-mode
   (set-lookup-handlers! 'lua-mode :documentation 'lua-search-documentation)
   (set-electric! 'lua-mode :words '("else" "end"))