Capture screenshot of a single DOM node via API

<p>here's the full <a href="https://github.com/letsvalidate/api" rel="ugc">doc</a> and the screenshotting based on <a href="https://chromium.googlesource.com/chromium/src/+/lkgr/headless/README.md" rel="ugc">headless chrome</a></p> <p>here's <a href="https://api.letsvalidate.com/v1/thumbs?url=stackoverflow.com&amp;selector=%23question-mini-list" rel="ugc">the example</a> which captured questions list of stackoverflow site</p> <p>what's your thought? your feedbacks are very welcome :)</p>