Create conversions for objects and scene-options

[mwfarb]

Some useful conversion libraries:

• https://github.com/primaryobjects/unity-to-aframe, Last edit 2021
• ...was forked from...
• https://github.com/umiyuki/UnityAFrameExporter, Last edit 2015

[mwfarb]

Examples that may help translate:

• https://stemkoski.github.io/A-Frame-Examples
• https://github.com/stemkoski/A-Frame-Examples

[mwfarb]

Advanced primitive geometry: https://github.com/mattatz/unity-mesh-builder

[mwfarb]

Closed in #78