[docs] Update using-the-aframe-inspector.md (#2438)
[docs] Update using-the-aframe-inspector.md (#2438)

Could not find an explanation of how to refocus the viewport camera on an object for easier rotation before,
but happened to stumble upon it. Would also like to suggest adding some info about it to the 'h' hotkeys menu in-inspector.
jaxmolina/ar,chenzlabs/aframe,weddingdj/aframe,dmarcos/aframe,aframevr/aframe,RSpace/aframe,aframevr/aframe,chenzlabs/aframe,mkungla/aframe,wizgrav/aframe,googlecreativelab/aframe,mkungla/aframe,ngokevin/aframe,ngokevin/aframe,darkwing/aframe,RSpace/aframe,weddingdj/aframe,jaxmolina/ar,wizgrav/aframe,darkwing/aframe,dmarcos/aframe,googlecreativelab/aframe