Updated Readme and Added format for OCI

[7h3-3mp7y-m4n]

Description

Updated the flag for OCI

What does this PR do?

The main purpose of this PR is to improve the URI scheme so that users can look at the proper format to pull
oci://registry:port/repository:tag#file-name.provisioners.yaml same as score-k8s

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)
• New chore (expected functionality to be implemented)

Checklist:

• My change requires a change to the documentation.
  • I have updated the documentation accordingly.
• I've signed off with an email address that matches the commit author.

[mathieu-benoit]

LGTM