data-api-builder Add doc for how to push to external contributor's PR

Why make this change?

We are an open source project, and as such we have external contributors pushing changes to our repo. But sometimes we may need to make some adjustments to their PR in order to fix format, bugs, help get tests passing, etc. This doc helps to make that easier by expanding on one way to handle this scenario.

What is this change?

This is a doc that explains how to add a remote that represents the external contributor's fork of our repo, and then how to make changes and push to that remote.

How was this tested?

N/A

Sample Request(s)

N/A

Apr 18 '25 23:04 aaronburtle

/azp run

Apr 23 '25 00:04 Aniruddh25

Azure Pipelines successfully started running 6 pipeline(s).

Apr 23 '25 00:04 azure-pipelines[bot]

/azp run

Apr 29 '25 01:04 Aniruddh25

Azure Pipelines successfully started running 6 pipeline(s).

Apr 29 '25 01:04 azure-pipelines[bot]

/azp run

May 06 '25 22:05 RubenCerna2079

Azure Pipelines successfully started running 6 pipeline(s).

May 06 '25 22:05 azure-pipelines[bot]

/azp run

May 07 '25 00:05 RubenCerna2079

Azure Pipelines successfully started running 6 pipeline(s).

May 07 '25 00:05 azure-pipelines[bot]