Update vpython_3d.py
Update vpython_3d.py

added some documetation where missing.
Shekharrajak/mubosym,DocBO/mubosym,Shekharrajak/mubosym,skidzo/mubosym,DocBO/mubosym,skidzo/mubosym,DocBO/mubosym,skidzo/mubosym,Shekharrajak/mubosym