Add minecraft:double_plant to overwritable blocks

[alphapapa]

Hi,

I'm enjoying Davinci's a lot, but when trying to land aircraft, I'm constantly running into double-tall grass blocks keeping them elevated an extra block when landing, making it hard to climb back inside.

I added minecraft:double_plant to the overwritable_blocks list in the config file, and it fixed it.

I would send a PR, but I don't know Java, and I don't know the correct Blocks.BLOCK-type object to add to the list in the code.

Thank you very much for your work on these mods!

[alphapapa]

It might also be good to add minecraft:red_flower and minecraft:yellow_flower, as these tend to prevent disassembly in plains.