Improve documentation site

[OrKoN]

• [ ] Create a landing page in for the website (currently we copy the repo's main README)
• [ ] Create separate README's for puppeteer and puppeteer-core (puppeteer-core examples don't work)
• [ ] Have a separate README for the mono repo
• [ ] Improve the structure to be as following:

Getting started

• [ ] What is Puppeteer?
• [ ] Installation (cover install and configuration)
• [ ] System requirements (mention Node/TS version by Puppeteer and hardware requirements by browsers)
• [ ] First script

Core concepts

• [ ] Browser Management
• [ ] Page Interaction
• [ ] JavaScript Execution
• [ ] Network Control

Advanced Topics

• [ ] Debugging
• [ ] Interception
• [ ] Headless mode
• [ ] Screenshots and PDFs
• [ ] Cookies
• [ ] File uploads and downloads

Browser support

WebDriver BiDi support

Community

• [ ] Contributing
• [ ] Troubleshooting
• [ ] Links

[OrKoN]

cc @Lightning00Blade @matthiasrohmer

[prajjwal-mathur]

Hello Alex, May I work on this? Also, I am not sure about how the first part is supposed to be done:

move documentation out of the repo's README to /docs Readme should link to the website instead.