update docs
update docs

keisuke-umezawa/chainer,cupy/cupy,keisuke-umezawa/chainer,okuta/chainer,keisuke-umezawa/chainer,pfnet/chainer,wkentaro/chainer,kashif/chainer,chainer/chainer,okuta/chainer,niboshi/chainer,cupy/cupy,tkerola/chainer,aonotas/chainer,wkentaro/chainer,wkentaro/chainer,jnishi/chainer,ktnyt/chainer,kiyukuta/chainer,ktnyt/chainer,hvy/chainer,okuta/chainer,niboshi/chainer,chainer/chainer,jnishi/chainer,okuta/chainer,ronekko/chainer,chainer/chainer,cupy/cupy,ktnyt/chainer,anaruse/chainer,ktnyt/chainer,niboshi/chainer,cupy/cupy,jnishi/chainer,rezoo/chainer,wkentaro/chainer,jnishi/chainer,hvy/chainer,niboshi/chainer,chainer/chainer,hvy/chainer,hvy/chainer,delta2323/chainer,keisuke-umezawa/chainer,ysekky/chainer