frontend: edit docs for playwright

[vyncent-t]

Update Documentation for Local Playwright End-to-End Tests

Description

This PR updates the existing documentation to include more detailed instructions on setting up and running local Playwright end-to-end tests. The enhancements aim to provide developers with clear guidelines on how to effectively utilize Playwright for testing their local developments, ensuring that they can quickly and efficiently verify changes before deployment.

Changes

• [x] Expanded the documentation to include step-by-step setup instructions for running Playwright locally.
• [X] Added options for preferences using configurations to playwright.config.ts

Verification

• [x] Ensured that all new documentation content is clear, accurate, and easy to follow.
• [x] Tested the setup instructions and test execution steps to ensure they are applicable and functional.
• [x] Reviewed the documentation for technical accuracy and coherence with existing documentation standards.

[sniok]

Something that could be useful is a development guide, like how to create, change and validate tests and also how to run tests against a local frontend build. Also we should probably mention the playwright --ui[0] option which I think is really useful

[0] https://playwright.dev/docs/test-ui-mode

[joaquimrocha]

@skoeva Can you confirm/test these steps?

[vyncent-t]

rebased and added a section for the UI mode