[Fish] Updates for fish 2.1

Accepting an autosuggestion is now bound to C-e, which works for me.
[Vim] Use s: where appropriate
[Vim] Update plug-ins
[Vim] Improve how joining lines works

- set nojoinspaces (do not insert two spaces after period)
- Remove extraneous comment char when joining
[Vim] Add heading
[Vim] Add template for Vim documentation