Links to moves/variations, and link previews for them

[shinuito]

Lets update the Shortcuts Docs!

Not strictly a keyboard shortcut, but you can make a link a game link be to a particular numbered move by adding /{insert move number} to the game url. So for example https://online-go.com/game/425048 goes to game number 425048, and https://online-go.com/game/425048/92 goes to move 92 in that game. See https://forums.online-go.com/t/new-feature-skip-to-move-with-url