All maps need extracted, and their assets
merged into the main pk3.

Hub script is in "RandomMap.wad by LJ Sonic"
It includes the teleporter map, and two 
example maps, both of which should be removed.

If I remember correctly, it has a range of
maps in its lua script, it'll need to be
changed from 02,03 to H1-H4 
(their actual)

NOTE: "HUB.wad by Seaballer" 
doesn't have a bonus campaign exit
I will add it myself,

Remove "MAP02" and "MAP03" from "RandomMap.wad"
but keep "MAP01"

Hub maps will use extended mapnum H.

RandomMap.wad -> MAPH0

The other four files can use
MAPH1-MAPH4. It doesn't matter which 
stage has which mapnum though.
So you can probably just do what's quickest.