Improve async communication guide
Created by: felixfbecker
Saw the new async comms guide, which has fantastic content, and saw some opportunities to improve the appearance and accessibility.
- Self-host videos and captions on sourcegraphstatic.com instead of on Google Drive. The Google Drive player had a low-quality image, distorted the preview image and had black bars while playing. It looks a lot more high-quality like this imo, using the native browser video player instead of Google Drive's. Also, I turned the captions on by default, which I think is a nice touch. All the assets can still easily be updated in our GCP file storage: https://console.cloud.google.com/storage/browser/sourcegraph-assets/handbook/async-communication?project=sourcegraph-dev
- Make one-pager an accessible SVG (can be read by screen readers, and text is selectable)
- Some smaller fixes to make links more accessible.
Before
After
Tested in Chrome, Firefox and Safari.