[docs] add LRN layer to tutorial/layers
[docs] add LRN layer to tutorial/layers

longjon/caffe,tackgeun/caffe,tackgeun/caffe,CZCV/s-dilation-caffe,CZCV/s-dilation-caffe,tackgeun/caffe,wangg12/caffe,gnina/gnina,gnina/gnina,gnina/gnina,wangg12/caffe,longjon/caffe,wangg12/caffe,gogartom/caffe-textmaps,gogartom/caffe-textmaps,gnina/gnina,CZCV/s-dilation-caffe,gogartom/caffe-textmaps,gnina/gnina,longjon/caffe,tackgeun/caffe,wangg12/caffe,gnina/gnina,CZCV/s-dilation-caffe,gogartom/caffe-textmaps,longjon/caffe