Merge pull request zziz#12 from BruceZhe/patch-1

Update CONTRIBUTING.md

Author: zziz

CONTRIBUTING.md

@@ -1,3 +1,3 @@
-If you don't see your paper in the list, please make a pull request or open an issue so that we can do it for you.   
-If you find a mistake (such as wrong repository for a paper), please make a pull request or open an issue.  
-For comments and suggestions for improving this repository, please do it [here](https://github.com/zziz/pwc/issues/1).  
+If you don't see your paper in the list, please make a pull request or open an issue so that we can do it for you;
+If you find a mistake (such as wrong repository for a paper), please make a pull request or open an issue;
+For comments and suggestions for improving this repository, please do it [here](https://github.com/zziz/pwc/issues/1).