From :h :Man:
> when running `man` from the shell and with that `MANPAGER` [='nvim
> +Man!'] in your environment, `man` will pre-format the manpage using
> `groff`. Thus, Nvim will inevitably display the manual page as it was
> passed to it from stdin. One of the caveats of this is that the width
> will _always_ be hard-wrapped
Since I actually don't like `g:man_hardwrap=0`/`MANPAGER=999` (e.g.
scrolling can be a mess with very long wrapped lines), add an
autocommand that is meant to reload the manpage through `:edit` after
every resize, so that its hard-wrapping adjusts to the new size.
This is slightly hacky, but does its job quite well.
Move the man.vim into after/ftplugin so that it overwrites the `set
wrap` of the global ftplugin, which I want turned off, since it messes
with the buffer shortly when resizing.
