mushroooms

0.0.20 update:

Technical update to update to latest ewc version. It brings huge performance gains and simplifies developpement.

Additions:

• added new rock type in sakura forest

Changes:

• Changed how arch in sakura generates to be more random from one to other.

Fixes:

• fixed mushrooms based on structure not generating correctly(fertile mushroom and green mushroom)
• fixed bush not generating in colorful plains
• fixed sakura arch not overriding water, leaves, and dirt