Add documentation for Signed Commits Requirement to Contributing Docs

[phenixblue]

What would you like to be added:

Need to add verbiage to specify the requirement for signed commits for all contributions to the Contributing Docs

Why is this needed:

More clarity for prerequisites for new contributors.

[pramod74]

Hi @phenixblue,

I would like to take up this issue. Is there some specific verbiage related to requirement for signed commits that needs to be added?

Thanks,
Pramod

[phenixblue]

Hello @pramod74 ,thanks for offering to help.

Nothing specific other than some verbiage that describes commit signing as a requirement.

I think it should probably go in the Submitting a PR section.

It would be good to link to Github's documentation on setting up commit signing

[pramod74]

Thanks, @phenixblue.

I have made an attempt and raised a PR. Kindly review.