I wanted to add syntax highlighting for for .tmux.conf file, so I add this file to bat/syntaxes/

https://raw.githubusercontent.com/gerardroche/sublime-tmux/master/Tmux.sublime-syntax

I then bat cache -b and try viewing my .tmux.conf file, but it is still plain with no syntax highlighting. Have I missed something or does this file not work with bat for some reason? Tmux and the file extensions do appear with bat -L.