Update contributing file

[Emma Dawson]

Step 12 of the CONTRIBUTING.md file is about committing your changes.

12. Commit your changes:

Please update to

12. Commit your changes and provide a meaningful commit message:

Unsure how to write a meaningful commit message? Check out this article about [How to Write a Good Git Commit Message](https://blog.ossph.org/how-to-write-a-good-git-commit-message/#:~:text=To%20set%20up%20a%20Git,t%20meet%20the%20specified%20format.)

[Diwakar Kashyap]

please assign this to me 😁

[Emma Dawson]

Sure, go ahead 😄

[Diwakar Kashyap]

is this OK ?

[Emma Dawson]

Looks good 👍🏻

[Diwakar Kashyap]

please check PR #338