For the past week or so I've been banging my head against a series of complex autoconf scripts for some packages and the lack of syntax highlighting for this type of file makes an unpleasant job more difficult. This is clearly not a super common file type but they do show up with some regularity in R package development.
As a one off, adding support for this specific filetype would be something I'd find personally useful at the moment, but in terms of a more generally useful feature has any thought been given to allowing user defined syntax highlighting configurations? e.g. a user is able to provide / specify a tmbundle or something similar which is then associated with a particular file extension?