added git learning resource

Author: Mannuel25

CONTRIBUTING_GUIDELINES.md

@@ -124,7 +124,8 @@ We want your work to be readable by others; therefore, we encourage you to note
 ## 🤔Need more help?
 You can refer to the following articles on basics of Git and Github and also contact me, in case you are stuck:
 - [Forking a Repo](https://help.github.com/en/github/getting-started-with-github/fork-a-repo)
-- [Cloning a Repo](https://help.github.com/en/desktop/contributing-to-projects/creating-an-issue-or-pull-request)
+- [Creating an issue or pull request](https://help.github.com/en/desktop/contributing-to-projects/creating-an-issue-or-pull-request)
+- [Cloning a Repo](https://docs.github.com/en/desktop/contributing-and-collaborating-using-github-desktop/adding-and-cloning-repositories/cloning-a-repository-from-github-to-github-desktop)
 - [How to create a Pull Request](https://opensource.com/article/19/7/create-pull-request-github)
 - [Getting started with Git and GitHub](https://towardsdatascience.com/getting-started-with-git-and-github-6fcd0f2d4ac6)
 - [Learn GitHub from Scratch](https://lab.github.com/githubtraining/introduction-to-github)