doc: clarify lua language server setup

lua/plugins/astroui.lua

@@ -2,7 +2,8 @@ if true then return {} end -- WARN: REMOVE THIS LINE TO ACTIVATE THIS FILE
 
 -- AstroUI provides the basis for configuring the AstroNvim User Interface
 -- Configuration documentation can be found with `:h astroui`
--- NOTE: We highly recommend setting up the Lua Language Server (lua_ls) as this provides autocomplete and documentation while editing
+-- NOTE: We highly recommend setting up the Lua Language Server (`:LspInstall lua_ls`)
+--       as this provides autocomplete and documentation while editing
 
 ---@type LazySpec
 return {