Added a pre-commit config file and reformatted all the files accordingly by using it.

examples/heterogeneous_soil.in

@@ -11,4 +11,4 @@
 #fractal_box: 0 0 0 0.15 0.15 0.070 1.5 1 1 1 50 my_soil my_soil_box
 #add_surface_roughness: 0 0 0.070 0.15 0.15 0.070 1.5 1 1 0.065 0.080 my_soil_box
 
-#geometry_view: 0 0 0 0.15 0.15 0.1 0.001 0.001 0.001 heterogeneous_soil n
+#geometry_view: 0 0 0 0.15 0.15 0.1 0.001 0.001 0.001 heterogeneous_soil n