better mount for SO-101 robot arm controller board

The original board mount didn't work for me, so I designed a better mount for the waveshare servo controller board for the SO-101 robot arms.There are two versions. One with 1.8mm holes to directly screw in M2 screws which works best for me. I made another version with 3.2mm holes for brass inserts before. This works fine, but in the end I prefered the direct screw in version since it is more convenient. I included both versions in the profile.