Normally, vim-haredoc tries to display coloured output, which is what
haredoc(1) does by default, or when passed the -Ftty option.
Assuming neovim cannot handle such output and wants plaintext, normally
one would ask haredoc(1) for plaintext with -Fhare. However, recently
this feature has been removed for reasons I don't know, and I'm
discussing this on IRC. Feel free to join us at #hare on
<irc.libera.chat>. I'd rather the upstream be fix than we do a