basic-writing-and-formatting: add raw=true also for images of same repo

[phil-blain]

It seems it is sometimes necessary to use the '?raw=true' parameter,
mentioned on the "In issues, pull requests and comments of another
repository" line of the table, even if the image linked to is in the
same repository as the issue or pull request.

Add it to the example in the line "In issues, pull requests and comments
of the repository" also.

[github-actions]

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Content directory changes

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Source	Preview	Production	What Changed
get-started/writing-on-github/getting-started-with-writing-and-formatting-on-github/basic-writing-and-formatting-syntax.md	fpt ghec ghes@ 3.5 3.4 3.3 3.2 3.1 ghae	fpt ghec ghes@ 3.5 3.4 3.3 3.2 3.1 ghae

[ramyaparimi]

@phil-blain
Thanks so much for opening a PR! I'll get this triaged for review ⚡

[akenneth]

Lgtm!

[cmwilson21]

This looks great! Thanks for contributing to the docs! I'll get this merged once the tests have all passed.

[github-actions]

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