GitLab

* [Bug Fix][Example] hgp-sl: More info for running

* change list to table

* change dataset summary in gxn and sagpool

* remove redundent
Co-authored-by: Tong He <hetong007@gmail.com>

* add sagpool example for pytorch backend

* polish sagpool example for pytorch backend

* [Example] SAGPool: use std variance

* [Example] SAGPool: change to std

* add sagpool example to index page

* add graph property prediction tag to sagpool
Co-authored-by: zhangtianqi <tianqizh@amazon.com>