wiki: redirect everything to go.dev/wiki For #61940.
Revert db38bcc7dc27dd2bc8609dd7f3b3619ba20cc515...4bea0f0ded884a9252ad1ffc85f8439aa108c359 on Screencasts
Add goscreencasts.io. A web site for learning Go.
Updated Screencasts (markdown)
Added new course and video.
Added new videos
Added 2 new videos
Added new video link