Updated index.md

[ritulsriva]

Added more resources to the article

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[RandellDawson]

Move the following to be outside the code block:

You can refer to this article for deeper insight into regression  
https://www.analyticsvidhya.com/blog/2017/06/a-comprehensive-guide-for-linear-ridge-and-lasso-regression/

[ritulsriva]

I have added the resource article outside the codeblock which I mistakenly inserted inside the codeblock in my previous commit.

Commit was added to correct issue

[cmccormack]

This looks good to me. Thank you for your contribution!

[moT01]

Looks good @ritulsriva, thanks for contributing to freeCodeCamp! In the future, be sure to fill out the checklist in the PR template provided. Thanks!