fix: disable syntax highlighting for input buffer

[oskarrrrrrr]

When syntax is enabled Neovim tries really hard to provide syntax highlighting. This is the simplest way I found to disable it for just one buffer.

Setting syntax = '' when the buffer is created is not enough, it will get overwritten on changes to the buffer and setting syntax = '' on buffer change wasn't 100% reliable for some reason.

Buffer scoped autocmds are cleaned up when the buffer is destroyed.

Fixes: #112

[dmtrKovalenko]

why do we need to do this on autocmd if we can set the option directly on a buffer when creating it

[oskarrrrrrr]

Setting it once is not enough. Neovim tries to guess the file type as you type and it will overwrite it.

This is what happens when you set it just once, immediately after opening the search:

and after you type something that looks like Lua:

We can see that Neovim overwrites the value.

[dmtrKovalenko]

with your changes I can still see the highlights in the prompt

[oskarrrrrrr]

I just double checked and it works for me. Can you open a new neovim instance, open fff and run :verbose set syntax? (you need to press first to escape the prompt) and then type "if" in the prompt and run the command again?

[dmtrKovalenko]

this is what I get

20:27:29 msg_show.list_cmd   verbose set syntax?   syntax=fff_input

while there is still syntax highlighting

[dmtrKovalenko]

sorry it's me being dumb