Document assign reviewer feature

[ivanayov]

This adds usage instructions to the README

Signed-off-by: Ivana Yovcheva iyovcheva@vmware.com

Motivation and Context

• I have raised an issue to propose this change (required)

How Has This Been Tested?

N/A

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I've read the CONTRIBUTION guide
• I have signed-off my commits with git commit -s
• I have added tests to cover my changes. N/A
• All new and existing tests passed. N/A

[alexellis]

@ivanayov we need this in the user guide too please.

[ivanayov]

It's now updated

[alexellis]

LGTM