feat(nvim): use nvim as default, create vimrc from scratch

Previously, I used a `vimrc.local` file to extend a vim config by spf13,
however, I felt it had a lot I did not require, therefore, I have
stripped it and created my own vimrc, which in turn updates a new
`nvimrc` for the new NeoVim.

I am using Pathogen as the bundle manager, and have put it into the
autoload directory of my vim directory alongwith the bundles I am using.

The bundles have been added as submodules.