[Articles, suggestion] Allow the moving of blocks around

[liamegan]

Probably easiest, given how long blocks can get, to do it using buttons / keystrokes.

[GemN]

We cannot use just arrows because it may cause problems for some blocks (table that navigate with arrows).
As a shortcut, I think we should at least do CMD/Ctrl+ArrowUp or CMD/Ctrl+ArrowDown), and also put "move up / move down" in GUI options.

[ciphrd]

We can have, like in notion, a drag'n'drop button to move the blocks.