feat: XCHG-15232 update publish app guide with the new Adobe Exchange flow

[zinap-ensemble]

Description

I am a developer on the Adobe Exchange team. We recently updated the App Builder workflows and design, so I created this PR to align the public documentation with the latest flow.

These changes have not been deployed to Adobe Exchange production yet, so please hold off on merging this PR. I will confirm the deployment dates and update this PR once I have the exact timeline.

Related Issue

https://jira.corp.adobe.com/browse/XCHG-15232

Motivation and Context

How Has This Been Tested?

Screenshots (if appropriate):

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)

Checklist:

• I have signed the Adobe Open Source CLA.
• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.

[pru55e11]

Approving on behalf of Madhur