What follows is an example on how to use the "ActiveMods.txt" file for shrill or make one from scratch.
The basic setup is like this:

<ActiveSetup=1>


<Setup0>

<Setup1>
TechTree
NoMoreInstantdownDespair
MixedPioneerCost
TrainingYards_AdventurersGuilds

<Setup2>
TechTree



So setting <ActiveSetup=0> and the running Shrill would apply no mods at all and give you the base files. Setting it to 1 would give you all the mods listed and setting it to 2 would only load the mysterious tech tree mod.
If installing a new mod remember to add its name in
the profile you want it to be in and to run shrill.luac
to actually apply the mods. As usual a new game is required for any changes to show up.