Update new-tab-same-directory.md to mention OSC 9;9

[MattKotsenas]

The docs mention using a specific escape sequence, but they don't mention the name.

I've added a mention to OSC 9;9 as often shell themes / tools refer to the escape sequence by name. This gives users trying to enable this feature in their tools something to search for.

[MattKotsenas]

I'm open to better ways to mention the escape sequence name than in a parenthetical. I was trying to provide extra context in an unobtrusive way.

[learn-build-service-prod]

Learn Build status updates of commit 6a6d79e:

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TerminalDocs/tutorials/new-tab-same-directory.md	✅Succeeded	View

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[mattwojo]

@zadjii-msft / @nguyen-dows -- Could you review?

[nguyen-dows]

Hey @MattKotsenas, thanks for addition! Can you capitalize "osc to "OSC"?
Once that's fixed, then I can merge this PR in! :)

[MattKotsenas]

Hey @MattKotsenas, thanks for addition! Can you capitalize "osc to "OSC"? Once that's fixed, then I can merge this PR in! :)

Fixed!

Thanks for taking a look!

[learn-build-service-prod]

Learn Build status updates of commit 7fa7bda:

✅ Validation status: passed

File	Status	Preview URL	Details
TerminalDocs/tutorials/new-tab-same-directory.md	✅Succeeded	View

For more details, please refer to the build report.

For any questions, please:

• Try searching the learn.microsoft.com contributor guides
• Post your question in the Learn support channel

[nguyen-dows]

Looks good!

[nguyen-dows]

I have merged the PR. Thanks @MattKotsenas!