Jungle tweaks

[careeoki]

Tweaks based on Ikabod's requests.

Roughness value has been reduced.

Less mud patches in jungle/base. Adjusted the mud patches in jungle/thick

Removed monstera, ferns, and grass blocks from the ancient jungle. In their place, there is dead leaves, and lots of mushrooms growing from the dead plant matter. Some have even grown into giant mushrooms. (only the small variants)

And generally I went around and cleaned things up to reduce visual noise while keeping it lush feeling.

Things I didn't do from Ikabod's requests:

• I think still having mud patches is important for the jungle vibe (in base and thick biomes), thick grass shouldn't be growing under the canopy of large trees.
• I didn't add the rock subbiomes to the ancient jungle. The ancient jungles are pretty small, with lots of height already, so I think the rocks would clash into the giant trees in undesirable ways.
• I thought about basalt for the stone block, but the jungle is already quite dark, so slate provides a nice contrast as it's brighter.