[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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- [ ] **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
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- [ ] [WXS for
installer](https://github.com/microsoft/PowerToys/blob/main/installer/PowerToysSetup/Product.wxs)
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https://github.com/user-attachments/assets/5a5f16dc-52f7-4e9d-85db-173eddba5d6d

---------

Co-authored-by: Jiří Polášek <me@jiripolasek.com>

src/modules/cmdpal/Microsoft.CmdPal.UI/Strings/en-us/Resources.resw

@@ -399,7 +399,7 @@ Right-click to remove the key combination, thereby deactivating the shortcut.</v
     <value>Dock (Preview)</value>
   </data>
   <data name="SettingsButton.[using:Microsoft.UI.Xaml.Automation]AutomationProperties.Name" xml:space="preserve">
-    <value>Open Command Palette settings</value>
+    <value>Open Command Palette settings, shortcut Control plus comma</value>
   </data>
   <data name="ActivationSettingsHeader.Text" xml:space="preserve">
     <value>Activation</value>