Minetest_game: Develop the biomes for mgv7 floatlands

[paramat]

In default/mapgen.lua there are 3 placeholder biomes for floatlands as examples of how to add biomes to floatlands. These could be replaced by dedicated floatland biomes that are special in some way, or, the biomes could be a subset of surface biomes.

[Ferk]

Perhaps it would be cool if it used special biomes with fantasy nodes, so that finding floatlands would be more rewarding and "magical". Floating lands are not realistic anyway.

Maybe something crazy like a candyland with lolipop/candybar trees, chocolate blocks for dirt and cream for grass, like in Zool.

[paramat]

Something unrealistic is fine, just not candyland =)
I don't have the ideas, time or energy for coming up with new content for this, however if necessary i can add more of the surface biomes up there, and may do for the short term.

[tenplus1]

You could use any of the biomes and decorations from Ethereal NG mod :)