docs(api.md): Added cutoff values for scale option in page.pdf function (#3201)
docs(api.md): Added cutoff values for scale option in page.pdf function (#3201)

Added the cutoff values for the scale option in the page.pdf function call. Numbers based on chrome's warning message.
puppeteer/puppeteer,GoogleChrome/puppeteer,GoogleChrome/puppeteer,GoogleChrome/puppeteer,puppeteer/puppeteer,puppeteer/puppeteer,puppeteer/puppeteer