Playwright: Fixed docs related to fixed properties types "waitForNavigation" and "firefox"

[mirao]

Motivation/Description of the PR

It's a fix of docs which I forgot to commit to https://github.com/codeceptjs/CodeceptJS/pull/3401

Applicable helpers:

• [ ] WebDriver
• [ ] Puppeteer
• [ ] Nightmare
• [ ] REST
• [ ] FileHelper
• [ ] Appium
• [ ] Protractor
• [ ] TestCafe
• [x] Playwright

Applicable plugins:

• [ ] allure
• [ ] autoDelay
• [ ] autoLogin
• [ ] customLocator
• [ ] pauseOnFail
• [ ] coverage
• [ ] retryFailedStep
• [ ] screenshotOnFail
• [ ] selenoid
• [ ] stepByStepReport
• [ ] stepTimeout
• [ ] wdio
• [ ] subtitles

Type of change

• [ ] :fire: Breaking changes
• [ ] :rocket: New functionality
• [x] :bug: Bug fix
• [ ] :clipboard: Documentation changes/updates
• [ ] :hotsprings: Hot fix
• [ ] :hammer: Markdown files fix - not related to source code
• [ ] :nail_care: Polish code

Checklist:

• [ ] Tests have been added
• [x] Documentation has been added (Run npm run docs)
• [x] Lint checking (Run npm run lint)
• [x] Local tests are passed (Run npm test)