help: the whole sheet, walked by key

The help was a box narrower than the screen that had to be scrolled with
the mouse. It is now as big as the porthole, in newspaper columns that run
on to the right: h/l and j/k move a column, Ctrl-D/U and Space a screen,
g/G to either end. A row is never split between columns, and says what it
says before its first dash; / filters the rows by key or words, and shows
the ones left whole. The prose footer became an 'in the editor' group.

docs/wiki/Getting-Started.md

@@ -74,7 +74,7 @@ The rail of buttons on the right does the same as the keys, for a mouse.
    inbox of this space's board. Press `b` to see the board, and `b` again to go
    back.
 7. Press `T`. That is today's diary entry, started for you.
-8. Press `?` for the list of every key and command, and `Esc` to close it.
+8. Press `?` for the list of every key and command. `h` / `l` walk its columns, `/` narrows it down, and `Esc` closes it.
 
 On a phone the same things are buttons: the dock at the bottom has a new
 document, a new folder, the board, today's entry, an upload and a search, and