docs: UI Testing of Sapphire dApps with Playwright

[rube-de]

Description:

Lack of comprehensive documentation detailing the process of UI testing Sapphire dApps using Playwright. This omission hinders efficient testing and quality assurance efforts.

Expected:

The documentation should provide a step-by-step guide, including code examples, illustrating how to configure Playwright for testing Sapphire dApps, interact with UI elements, and assert expected outcomes.

Recommendations:

1. Create a new documentation section specifically addressing UI testing of Sapphire dApps with Playwright.
2. Include example code snippets demonstrating common UI testing scenarios.
3. Provide guidance on setting up the testing environment and configuring Playwright for Sapphire dApps.
4. Address potential challenges unique to testing dApps (e.g., handling asynchronous transactions, interacting with MetaMask).