JuliaML
added the PPI dataset
In this pull request, we add the PPI dataset from http://snap.stanford.edu/graphsage/#datasets
The PPI dataset is loaded in the same way as Reddit. We added a new file graphsage.jl, it provides the function load_graphsage_data. Most of the code in the original reddit.jl is copied into this function, and we added labels = stack(labels) to covert the labels of the PPI dataset from Vector{JSON3.Array} to a matrix.
We added ppi.jl, which defines the PPI dataset and loads data with this function. Now reddit.jl uses this function to load data as well.
Hi, thanks for the contribution and sorry for getting to you so late. This is a welcome addition. You just need to add the new dataset to the documentation, docs/src/datasets/graph.md
