adding docs
adding docs

pfnet/chainer,chainer/chainer,chainer/chainer,hvy/chainer,niboshi/chainer,hvy/chainer,wkentaro/chainer,chainer/chainer,niboshi/chainer,hvy/chainer,hvy/chainer,wkentaro/chainer,wkentaro/chainer,niboshi/chainer,niboshi/chainer,chainer/chainer,wkentaro/chainer