Update README.md

@RiyaGupta89, image wasn't showing due to incorrect link. I've fixed that too.

Author: harshita2216

news-app/README.md

@@ -40,9 +40,9 @@ npm start
 
 ## Screenshots
 
-![Demo1](public/news.png)
+![Demo1](/news-app/public/news.png)
 
-![Demo2](public/news1.png)
+![Demo2](/news-app/public/news1.png)
 
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