Add a proper keymap variable for the outline

[Townk]

• [x] Remove all treemacs bindings from the Outline;
• [x] Create a separate keybinding map for the Outline;
• [x] If evil-mode is enable, add evil keybindings the the keymap;

Requirement

As thee maintainer, I don't want to allow users to use treemacs bindings without explicit code for it.

Notes

Maybe I should create a minor mode here?