* Add hgat example
* Add experiment
* Clean code
* clear the code
* Add index in README
* Add index in README
* Add index in README
* Add index in README
* Add index in README
* Add index in README
* Change the code title and folder name
* Ready to merge
* Prepare for rebase and change message passing function
* use git ignore to handle empty file
* change file permission to resolve empty file
* Change permission
* change file mode
Co-authored-by: Chen <chesirui@3c22fbe5458c.ant.amazon.com>
Co-authored-by: Tianjun Xiao <xiaotj1990327@gmail.com>