GitLab

* [Doc] updated readme

* contribution guide change

* small edits

* add perf #

* Update README.md

* Update README.md

* add others...

* rewrite scalability

* model & code links

* some note for treelstm

* rewrite scalability

* update example readme

* mx example readme

* add results in readme

* mx rgcn readme

* change the signature of node/edge filter

* upd filter

* Support multi-dimension node feature in SPMV

* stable version

* hotfix

* upd tutorial

* upd README

[DOC][Model] Tree-LSTM example and tutorial