[DOCS] Updated instructions to view payments locally.

[1Copenut]

Are you removing, renaming or moving a folder in this PR?

• No, I'm not changing any folders (skip to TeamSites and delete the rest of this section)
• Yes, I'm removing, renaming or moving a folder

Did you change site-wide styles, platform utilities or other infrastructure?

• No
• Yes, and I used the proxy-rewrite steps to test the injected header scenario

Summary

• View Payments README were missing a step to view mocked payments locally. I added the missing step and made some formatting and text edits to improve clarity.

Testing done

• Proofread changes locally and viewed on GitHub for formatting accuracy

Acceptance criteria

Quality Assurance & Testing

• No sensitive information (i.e. PII/credentials/internal URLs/etc.) is captured in logging, hardcoded, or specs
• Documentation has been updated (link to documentation *if necessary)