Docs: Remove jestPlaywrightDebug ?

[thernstig]

https://github.com/playwright-community/jest-playwright#jestplaywrightdebug mentions the use of jestPlaywrightDebug. But with the support for PWDEBUG=1 jest is jestPlaywrightDebug needed anymore? If not it should be removed from the docs and code.

Sorry for not using the template but it feels way too elaborate for something like this that exists in the README.md 😝

[mmarkelov]

@thernstig this is helper function to simplify debugging process. But this is not related to jestPlaywright.debug() that we removed.

[thernstig]

I was aware, but I just did not see the reason for test.jestPlaywrightDebug. One can easily do if (process.env.PWDEBUG) in jest-playwright.config.js. I thought it might simplify some logic for you and you could just describe how to use that env var.