Add Winter Drop (1.21.4) blocks

[stwalkerster]

I've been meaning to push this up for a while, but there's still an issue with the biome colouring not being quite correct for the Pale Garden biome. It's as close as I think I can get it without substantially more invasive changes though, and it's something that can be fixed later.

[Derjik]

Hello, great thanks for implementing the new biome !

I just tested it today, I'd suggest adding a color of your choice for the Biome Overlay in the default_biomes[] array of overlay-biomes.c : currently, Pale Gardens show no distinctive colouring (see screenshot below)

Edit : or maybe make it so that it maps just like other "Forest"-type biomes ?

Thanks again for your work, much appreciated o/

[stwalkerster]

I totally forgot about the biome overlay; thanks for pointing it out.

That said, there appears to be a substantial amount of oddness with the biome overlay. I can see cherry grove biomes have the same issue:

There's the ocean which is rendering without any overlay at all, despite having an overlay in the code:

Also mushroom fields (yes, biome overlay is enabled in this screenshot):

There's this sunflower plains biome which renders the same as the river surrounding it:

I think I'm going to look at the biome overlay more generally in a different PR. I suspect I'm not the first person to have forgotten about it, since the order in overlay-biomes.c is substantially different to the order in biomes.h. I think bodging in an overlay colour for just Pale Garden is going to require setting biome colours for a bunch of different biomes, and it'd be better for me to do it once and correctly (and hence, not in this PR - #79)