refactor: combine files to align with plugin organization and add more comments

lua/community.lua

@@ -1,6 +1,9 @@
 if true then return {} end -- REMOVE THIS LINE TO ACTIVATE THIS FILE
 
 -- AstroCommunity: import any community modules here
+-- We import this file in `lazy_setup.lua` before the `plugins/` folder.
+-- This guarantees that the specs are processed before any user plugins.
+
 ---@type LazySpec
 return {
   -- TODO: Remove branch v4 on release