Rename Settings UI label from “Shortcut Guide V2” to “Shortcut Guide” (#48151)

## Summary of the Pull Request

This updates PowerToys Settings to remove the obsolete “V2” suffix from
the Shortcut Guide module name. The UI now consistently shows **Shortcut
Guide**.

## PR Checklist

- [ ] **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
- [x] **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

## Detailed Description of the Pull Request / Additional comments

- **Settings navigation label**
  - Updated `Shell_ShortcutGuide.Content` to `Shortcut Guide`.
- **Module title**
  - Updated `ShortcutGuide.ModuleTitle` to `Shortcut Guide`.
- **OOBE title**
  - Updated `Oobe_ShortcutGuide.Title` to `Shortcut Guide`.

```xml
<data name="Shell_ShortcutGuide.Content" xml:space="preserve">
  <value>Shortcut Guide</value>
</data>
```

## Validation Steps Performed

- N/A for behavior-level validation in this description (change is
limited to localized display strings).

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>