feat(dotfiles): add some macOS style fallbacks
feat(dotfiles): add some macOS style fallbacks

At this point this is really just OCD (brought to you by the power of
Vim macros).

Examples:

- Type Option-n Shift-b and see "˜B"
- Type Option-e x and see "´x"
- Type Option-u } and see "¨}"

etc.

wincent/wincent,wincent/wincent,wincent/wincent,wincent/wincent,wincent/wincent,wincent/wincent,wincent/wincent,wincent/wincent