[docs] fix videosphere source path typo
[docs] fix videosphere source path typo

jaxmolina/ar,wizgrav/aframe,chenzlabs/aframe,googlecreativelab/aframe,RSpace/aframe,ngokevin/aframe,ngokevin/aframe,aframevr/aframe,wizgrav/aframe,dmarcos/aframe,aframevr/aframe,chenzlabs/aframe,weddingdj/aframe,mkungla/aframe,RSpace/aframe,darkwing/aframe,darkwing/aframe,weddingdj/aframe,jaxmolina/ar,googlecreativelab/aframe,dmarcos/aframe,mkungla/aframe