Allow Grass to Spread on Grass Tiles

[Hollowstyx]

Suggestion to allow tall grass to spread over grass tiles, either in base game or as a toggleable setting.

- Would slightly buff keeping livestock on maps with grass tiles, letting you better utilize the green areas for your animals.
- It looks a bit silly when it doesn't (as pictured above), leaving cut off dirt edges and an odd looking division.
- It looks natural when it DOES spread over grass tiles, and looks better when animals graze and don't leave barren dirt behind (which also reflects how it would look irl, which is fun).
- Who is mowing my lawn??