Fix broken examples in npm registry docs

[Joshwanda17]

Fixes three issues in working-with-the-npm-registry.md:

• 'Installing packages from other organizations' showed the identical @namespace line twice instead of two distinct examples, defeating the purpose of the section
• Stray space in the GHES publishConfig registry URL (npm. HOSTNAME/)
• Double slash in the GHES .npmrc authToken line, which would prevent npm from matching the token to the registry

[github-actions]

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Table of review links

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The table shows the files in the content directory that were changed in this pull request. This helps you review your changes on a staging server. Changes to the data directory are not included in this table.

Source	Review	Production	What Changed
packages/working-with-a-github-packages-registry/working-with-the-npm-registry.md	fpt ghec ghes@ 3.22 3.21 3.20 3.19 3.18 3.17	fpt ghec ghes@ 3.22 3.21 3.20 3.19 3.18 3.17

Key: fpt: Free, Pro, Team; ghec: GitHub Enterprise Cloud; ghes: GitHub Enterprise Server

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[armanayub1973]

Please sir I need you help my country Bangladesh

[janiceilene]

Thanks for opening a PR @Joshwanda17! I'll get this triaged to the team for review.

[mchammer01]

@Joshwanda17 👋🏻 - thank you for these fixes, LGTM ✨
Let's merge this

[github-actions]

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