`toggle_help` action should not switch to the help buffer

Currently when you trigger `toggle_help`, the cursor jumps to the help buffer. I can't think of why the user would want the cursor in this read-only buffer-- better to open the buffer and leave the cursor where it is.

Start at the `toggle_help` action and trace how it opens the help buffer. Verify the current cursor movement and the surrounding buffer-handling behavior. Done means the help buffer opens while the cursor remains in its previous location.

Written by the indexing model from the issue text.