[cmdpal] Announce Shortcut key information (#46164)

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## Summary of the Pull Request
Add audio text about shortcut key for settings on the settings button

This is part of the a11y bug batch.
User Impact:
Users relying on assistive technologies may be unaware of shortcut keys,
reducing efficiency and making it harder to use the Command Palette
effectively.

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## PR Checklist

- [ ] Closes: #xxx
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issues) -->
- [ ] **Communication:** I've discussed this with core contributors
already. If the work hasn't been agreed, this work might be rejected
- [ ] **Tests:** Added/updated and all pass
- [ ] **Localization:** All end-user-facing strings can be localized
- [ ] **Dev docs:** Added/updated
- [ ] **New binaries:** Added on the required places
- [ ] [JSON for
signing](https://github.com/microsoft/PowerToys/blob/main/.pipelines/ESRPSigning_core.json)
for new binaries
- [ ] [WXS for
installer](https://github.com/microsoft/PowerToys/blob/main/installer/PowerToysSetup/Product.wxs)
for new binaries and localization folder
- [ ] [YML for CI
pipeline](https://github.com/microsoft/PowerToys/blob/main/.pipelines/ci/templates/build-powertoys-steps.yml)
for new test projects
- [ ] [YML for signed
pipeline](https://github.com/microsoft/PowerToys/blob/main/.pipelines/release.yml)
- [ ] **Documentation updated:** If checked, please file a pull request
on [our docs
repo](https://github.com/MicrosoftDocs/windows-uwp/tree/docs/hub/powertoys)
and link it here: #xxx

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## Detailed Description of the Pull Request / Additional comments

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https://github.com/user-attachments/assets/5a5f16dc-52f7-4e9d-85db-173eddba5d6d

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Co-authored-by: Jiří Polášek <[email protected]>