[Doc] Add two papers to Awesome papers list (#2511)

* PPIDataset

* Revert "PPIDataset"

This reverts commit 264bd0c960cfa698a7bb946dad132bf52c2d0c8a.

* data pipeline user guide

* remove chapter numbers

* Update data.rst

* image in dataset userguide

* update links using ref

* modify the link of save_graphs and load_graphs in dataset user guide

* move image to s3 server.

* fix links and ref

* Hide implementations that may cause confusions to the user

* add papers

* fix number of classes in Amazon Cobuy datasets

* add two papers to Awesome paper list

* Update README.md

README.md

@@ -275,6 +275,9 @@ We are currently in Beta stage.  More features and improvements are coming.
 
 1. [**PGM-Explainer: Probabilistic Graphical Model Explanations for Graph Neural Networks**](https://proceedings.neurips.cc/paper/2020/file/8fb134f258b1f7865a6ab2d935a897c9-Paper.pdf), *Minh N. Vu, My T. Thai*
 
+1. [**Discourse-Aware Neural Extractive Text Summarization**](https://www.aclweb.org/anthology/2020.acl-main.451.pdf), ACL'20, *Jiacheng Xu, Zhe Gan, Yu Cheng, Jingjing Liu*
+
+1. [**Learning Robust Node Representations on Graphs**](https://arxiv.org/abs/2008.11416), *Xu Chen, Ya Zhang, Ivor Tsang, Yuangang Pan*
 
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