Blasted Barrens 1.0.1

Added two entity type tags (both only contain vanilla creepers by default).
- blasted_barrens:resizable: when Pehkui is installed, mobs added to this tag have a 12.5% chance to be up to 50% larger and 25% slower upon spawning in the blasted barrens.
- blasted_barrens:low_vision: mobs added to this tag have their vision reduced by about 80% in blasted barrens biomes. However, visibility is actually higher for Pehkui-upsized mobs, so they'll approach out of the fog from even farther away than usual. Maybe I'll make this configurable later :)