Add a license field where required

Author: TheGiraffe3

copyright

@@ -119,6 +119,7 @@ License: CC-BY-SA-4.0
 Files:
  images/land/taltahard*
 Copyright: Brigette Warner (https://pixabay.com/users/arttower-5337/)
+License: CC0
 Comment:
  Taken from https://pixabay.com/photos/arches-national-park-utah-moab-usa-51612/, and
  resized. According to Section 3 of the Pixabay Terms of Service, all images with a
@@ -132,6 +133,7 @@ License: CC0
 Files:
  images/land/sinsansun*
 Copyright: Steve Buissinne (https://pixabay.com/users/stevepb-282134/)
+License: CC0
 Comment:
  Taken from https://pixabay.com/photos/canola-fields-green-rolling-hills-1911392/, and
  resized. According to Section 3 of the Pixabay Terms of Service, all images with a