Updated GitHub desktop fork instructions

[warp-core]

Most of this description, and most of the changes here, are from #34151, I just made the changes requested in the last review that PR received before being closed.

Why: The current fork instructions for Github desktop were out of date with the latest Github desktop.

Closes: desktop/desktop#13165 (I realize this is an issue from a different repository, however in the comment thread of that issue you will see people mentioning that the issue arises because the docs here need updating.)

What's being changed (if available, include any code snippets, screenshots, or gifs): Minor documentation changes, inluding updating screenshots. The easiest way to see the changes would be to look at the PRs file changes.

Check off the following:

• A subject matter expert (SME) has reviewed the technical accuracy of the content in this PR. In most cases, the author can be the SME. Open source contributions may require an SME review from GitHub staff.
• The changes in this PR meet the docs fundamentals that are required for all content.
• All CI checks are passing and the changes look good in the preview environment.

[welcome]

Thanks for opening this pull request! A GitHub docs team member should be by to give feedback soon. In the meantime, please check out the contributing guidelines.

[github-actions]

👓 Previews for changed content

This comment is 🤖 automatically generated and will be overwritten every time changes are committed to this branch.

The table contains an overview of files in the content directory that have been changed in this pull request. It's provided to make it easy to review your changes on the review server. Please note that changes to the data directory will not show up in this table.

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Content directory changes

You may find it useful to copy this table into the pull request summary. There you can edit it to share links to important articles or changes and to give a high-level overview of how the changes in your pull request support the overall goals of the pull request.

Source	Preview	Production	What Changed
desktop/adding-and-cloning-repositories/cloning-and-forking-repositories-from-github-desktop.md	fpt ghec ghes@ 3.15 3.14 3.13 3.12 3.11 3.10	fpt ghec ghes@ 3.15 3.14 3.13 3.12 3.11 3.10
pull-requests/collaborating-with-pull-requests/working-with-forks/fork-a-repo.md	fpt ghec ghes@ 3.15 3.14 3.13 3.12 3.11 3.10	fpt ghec ghes@ 3.15 3.14 3.13 3.12 3.11 3.10

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Key: fpt: Free, Pro, Team; ghec: GitHub Enterprise Cloud; ghes: GitHub Enterprise Server
This table is posted from the Content Changes Table Comment workflow.

[warp-core]

Which naming style is preferred: "url" or "url-tab"?

[isaacmbrown]

@warp-core 👋 Thanks for the PR and linking to the desktop issue for context! I've added this to our review board.

@steveward If you have time, I'm wondering if you're up for reviewing this since you have the context from the issue. No worries if not, I'll leave it on a board so anyone can pick it up.

[steveward]

@isaacmbrown Will do!

@warp-core I'll take a look at this and will get back to you soon. Thanks for the PR!