Support wildcards/regex for filetypes

[winstliu]

See atom/language-make#16 for motivation. Currently it's not possible to specify a filetype that has a certain pattern to it, only an extension or complete filename.

[Ingramz]

Additional motivation atom/atom#2734 (comment)

#17 might be related?

[marco5chirico]

+1 👍

[deiga]

@marco5chirico Please refrain from commenting a thumbsup. Github supports reactions to posts already and you could subscribe to the issue. These don't create a useless notification for people following an issue