Change the 'scale' value to 0.5 for hill biome variants

The hill biome variants are currently just slightly more bumpy versions of the normal biomes, and most of the time aren't even noticeable, let alone Interneting or unique. Changing the 'scale' value in the biome data from 0.3 to 0.5 would make it possible for hills to generate in substantially more interesting ways, and though this change would be extremely easy to add to the game, it would improve the overall experience of exploring the game as well as adding the possibility to find interesting landmarks to build on. It would also nicely compliment the future mountain generation changes.