Issachari Evolved

Add a few new types Issachari to the raiding parties!  The water guardian, elder, and sniper have joined the ranks!

This mod was created as a part of the 2023 Monster Mash mod jam!  I asked ontoclasm (qud's artist) if he had ideas I should turn into a Monster Mash submission, and was quickly handed these three tiles with the comment: "always thought they could use a bit more variety, cool desert nomads that hit you with sick burns any time you try to talk to them? yes please!"  - I agree