fix readme typo
fix readme typo

mkungla/aframe,ngokevin/aframe,aframevr/aframe,dmarcos/aframe,ngokevin/aframe,chenzlabs/aframe,RSpace/aframe,mkungla/aframe,RSpace/aframe,wizgrav/aframe,chenzlabs/aframe,wizgrav/aframe,aframevr/aframe,dmarcos/aframe