[htmlmesh] hover on all elements and PR to threejs repo

[vincentfretin]

Generalize hover state to more elements and create a PR to threejs repo

• Hover on button AdaRoseCannon/aframe-htmlmesh#9

[vincentfretin]

Be a monthly sponsor so that I can work on it. Find other work you can sponsor at https://github.com/c-frame/sponsorship

[vincentfretin]

See the notes on the aframe wiki to know what htmlmesh can do.