Add instructions about when to preload the ROM vs not.

pool.lua

@@ -10,8 +10,16 @@ local hasThreads =
 		config.NeatConfig.Threads > 1
 local Runner = nil
 if hasThreads then
+	local warn = '========== When using threads, the ROM file to use comes from config.lua. Also, you do not need to start any ROM in the parent process.'
+	io.stderr:write(warn)
+	print(warn)
+
     Runner = dofile(base.."/runner-wrapper.lua")
 else
+	local warn = '========== The ROM must already be running when you only have one thread.'
+	io.stderr:write(warn)
+	print(warn)
+
     Runner = dofile(base.."/runner.lua")
 end
 

tools/status-overlay.lua

@@ -2,6 +2,10 @@ local base = string.gsub(@@LUA_SCRIPT_FILENAME@@, "(.*[/\\])(.*)", "%1").."/.."
 
 local set_timer_timeout, memory, memory2, gui, input, bit = set_timer_timeout, memory, memory2, gui, input, bit
 
+local warn = '========== The ROM must be running before running this script'
+io.stderr:write(warn)
+print(warn)
+
 local util = dofile(base.."/util.lua")
 local mem = dofile(base.."/mem.lua")
 local spritelist = dofile(base.."/spritelist.lua")