Vim: add functions#plaintext
Vim: add functions#plaintext

Sometimes I want to edit a file in "plaintext" mode. Not ready to make
this a default for ".txt" files yet, so it's a callable function only.

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