bug#41129: outline-mode: New keybindings for demote/promote/move-subtree

[Juri Linkov]

> Maybe these bindings could be in another minor-mode that
> could be enabled by those users that want them?
> outline-use-org-bindings-minor-mode.

bug#45147 implemented new mode outline-cycle-minor-mode
for Org-like TAB cycling in outline-minor-mode.

It's easy to customize outline-mode-cycle-map
and to bind M-left/right to outline-promote/demote:

(define-key outline-mode-cycle-map [(meta left)] 'outline-promote)
(define-key outline-mode-cycle-map [(meta right)] 'outline-demote)