Update CONTRIBUTING.md

Author: i-vishi

CONTRIBUTING.md

@@ -11,7 +11,9 @@
  * Please include a description for the algorithm that you are implementing. It doesn't matter if it's copied from somewhere as long as it helps people that are learning new algorithm.
  * Graphical examples would be very helpful too.
  * You can include tests as well.
- * Don't remove previous implementations of algorithms. Just add a new file with your own implementation.
+ * Don't remove previous implementations of algorithms. You can help in improving the current implementation by adding explanations and examples.
  * Beautify and clean up your code for easier reading
+ 
  ### Note:
+ * **Do not make a new issue unless required.**
  * If your PR is closed without any comment, it means that your PR does not meet the above criteria. Make sure your PR is **not Duplicate** and it should be **well-documented**.