[WXP-4951] Launch playground from documentation site

[rekha-m]

Jira Link: https://jira.corp.adobe.com/browse/WXP-4951

Designs: https://www.figma.com/design/aQEBb1loEEdvyFGO16B3fW/First-Mile-Dev-Journey-Improvements?node-id=104-233&t=N0a8sSYjkCoX2Klm-1
User journeys https://docs.google.com/document/d/1NBD5myv4kGMnuTFxMEpgb6Y0FpFz6G7df-v7u__UZog/edit?tab=t.0#heading=h.5w1yjfez7wur

https://git.corp.adobe.com/Horizon/hz/pull/205504/files
Launch playground from the documentation site.
Introduce a Launch code playground button in the docs,

• on clicking should open the playground if dev mode is already enabled.
• Should open DTOU dialog if not.

Related Issue

Motivation and Context

How Has This Been Tested?

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• I have signed the Adobe Open Source CLA.
• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.