Backup source of STL (No. 1)

• Backup list
• View the diff.
• View the diff current.
• View the diff for visual.
• View the backup.
• Go to STL.
  • 1 (2019-07-24 (Wed) 13:27:43)

* THREEJS [#l53871f7]
-   https://threejs.org/examples/webgl_loader_stl.html