Documentation/braille-console: convert it to ReST markup

- Fix identation for the document title;
- use monotonic fonts for paths;
- use quote blocks where needed;
- adjust spaces to properly format paragraphs;
- use :menuselection: and :kbd: for the menu item and keys;
- point too the right item at the menu;
- add it to the user book.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>