Update c.vim to toggle between kernel and normal c_vim mode.
Update c.vim to toggle between kernel and normal c_vim mode.

This is from @janlazo on junegunn/vim-plug answering on how to
add a "Project specific ftplugin" [1].

[1]: https://github.com/junegunn/vim-plug/issues/752

winksaville/scripts,winksaville/scripts