add readme about dists in dist/
add readme about dists in dist/

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