add generator definition file (.toml)

res/generators/default.toml

@@ -0,0 +1 @@
+biome_parameters = 0

res/generators/default/script.lua

@@ -1,5 +1,3 @@
-biome_parameters = 0
-
 biomes = {flat = {
     parameters = {},
     layers = {
@@ -9,7 +7,3 @@ biomes = {flat = {
         {height=-1, block="core:obstacle"}
     }
 }}
-
-function generate_heightmap(x, y, w, h, seed)
-    return Heightmap(w, h)
-end