chore: mark version v2.1.1 (puppeteer#5388)

chore: mark version v2.1.0 (puppeteer#5347)

This changes the Chromium revision to r722234 (Chrome 80.0.3987.0),
since that's the most recent version in the Chromium 80 range for
which a download exists for all supported platforms.

chore: mark version v2.0.0 (puppeteer#5078)

chore: mark version v1.20.0 (puppeteer#4928)

chore: mark version v1.19.0 (puppeteer#4744)

chore: mark version v1.18.1 (puppeteer#4628)

chore: mark version v1.18.0 (puppeteer#4606)

chore: mark version v1.17.0 (puppeteer#4467)

chore: mark version v1.16.0 (puppeteer#4421)

chore: mark version v1.15.0 (puppeteer#4346)