Add vim-nerdfont support for file icons

[krisfans]

Add vim-nerdfont support for file icons

[mmrwoods]

Thanks for the suggestion, this seems a good idea, but probably one that needs to wait until the existing devicons code is refactored a little to DRY things up. Once that's done supporting vim-nerdfont looks simple enough within the devicon code.

There is no timeframe for doing this refactoring, I started it some time ago, but ran into issues with early versions of vim 9.0 so abandoned it. I'll try to revisit it soon and add support for vim-nerdfont.

[mmrwoods]

Will be addressed by #75, which allows a user to override the function used to obtain devicon/nerdfont glyphs, e.g. let g:fuzzyy_devicons_glyph_func = 'nerdfont#find'