Add “How to submit a library” short note to CONTRIBUTING.md

[Dippp10]

@avelino ji,While there is a contributing guide, adding a very short section in the README that says “If you’d like to suggest a library, open a PR and follow this link…” will help make the process more visible to first-time contributors.
Skills: Markdown, linking to existing CONTRIBUTING file.

[Dippp10]

@ avelino ji, do assign hackoctoberfest-accepted label to above issue created by me.......do assign above issue number 5898 to me

[Aditya-myst]

Hi! I’d like to work on this issue. I’ll add a short “How to submit a library” note in the README that links to CONTRIBUTING.md. Thanks!

This PR will be part of #Hacktoberfest. 🙌