DOC: add interactive legend example
DOC: add interactive legend example

mpld3/mpld3,e-koch/mpld3,aflaxman/mpld3,mpld3/mpld3,jrkerns/mpld3,litaotao/mpld3,Jiangshangmin/mpld3,kdheepak89/mpld3,etgalloway/mpld3,danielballan/mpld3,giserh/mpld3,danielballan/mpld3,fdeheeger/mpld3,giserh/mpld3,mlovci/mpld3,e-koch/mpld3,kdheepak89/mpld3,CrazyGuo/mpld3,linearregression/mpld3,mlovci/mpld3,huongttlan/mpld3,jakirkham/mpld3,void32/mpld3,fdeheeger/mpld3,Jiangshangmin/mpld3,etgalloway/mpld3,litaotao/mpld3,keflavich/mpld3,linearregression/mpld3,keflavich/mpld3,jakirkham/mpld3,void32/mpld3,huongttlan/mpld3,jrkerns/mpld3,jayhetee/mpld3,jakevdp/mpld3,jakevdp/mpld3,CrazyGuo/mpld3,aflaxman/mpld3,jayhetee/mpld3