[Doc] Add two papers to Awesome Paper List (#3155)

* 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

* add four papers

* add two papers

* Add awesome papers

* Fix index in paper list

* Add paper to paperlist

* add two papers
Co-authored-by: Minjie Wang <wmjlyjemaine@gmail.com>

README.md

@@ -333,6 +333,10 @@ We are currently in Beta stage.  More features and improvements are coming.
 
 1. [**Enhancing Scientific Papers Summarization with Citation Graph**](https://arxiv.org/abs/2104.03057), AAAI'21, *Chenxin An, Ming Zhong, Yiran Chen, Danqing Wang, Xipeng Qiu, Xuanjing Huang*
 
+1. [**Graph Ensemble Learning over Multiple Dependency Trees for Aspect-level Sentiment Classification**](https://arxiv.org/abs/2103.11794), NAACL'21, *Xiaochen Hou, Peng Qi, Guangtao Wang, Rex Ying, Jing Huang, Xiaodong He, Bowen Zhou*
+
+1. [**Enhancing Scientific Papers Summarization with Citation Graph**](https://arxiv.org/abs/2104.03057), AAAI'21, *Chenxin An, Ming Zhong, Yiran Chen, Danqing Wang, Xipeng Qiu, Xuanjing Huang*
+
 1. [**Improving Graph Representation Learning by Contrastive Regularization**](https://arxiv.org/pdf/2101.11525.pdf), *Kaili Ma, Haochen Yang, Han Yang, Tatiana Jin, Pengfei Chen, Yongqiang Chen, Barakeel Fanseu Kamhoua, James Cheng*
 
 1. [**Extract the Knowledge of Graph Neural Networks and Go Beyond it: An Effective Knowledge Distillation Framework**](https://arxiv.org/pdf/2103.02885.pdf), WWW'21, *Cheng Yang, Jiawei Liu, Chuan Shi*
@@ -351,6 +355,10 @@ We are currently in Beta stage.  More features and improvements are coming.
 
 1. [**DIPS-Plus: The Enhanced Database of Interacting Protein Structures for Interface Prediction**](https://arxiv.org/abs/2106.04362), *Alex Morehead, Chen Chen, Ada Sedova, Jianlin Cheng*
 
+1. [**Coreference-Aware Dialogue Summarization**](https://arxiv.org/abs/2106.08556), SIGDIAL'21, *Zhengyuan Liu, Ke Shi, Nancy F. Chen*
+
+1. [**Document Structure aware Relational Graph Convolutional Networks for Ontology Population**](https://arxiv.org/abs/2104.12950), arXiv, *Abhay M Shalghar, Ayush Kumar, Balaji Ganesan, Aswin Kannan, Shobha G*
+
 </details>
 
 ## Installation