Custom file types

[danieroux]

• I have read the Clojure etiquette and will respect it when communicating on this platform.

Is your feature request related to a problem? Please describe.
We have .repl files, which are Transcriptor tests. We want to lint those when --lint <dir>.

Describe the solution you'd like
A CLI flag --custom-file-types repl,clj --lint <dir> to map the file type to lang clj. It will then include the custom type when looking in <dir>.

Describe alternatives you've considered
Making --lang mandatory if --custom-file-types is specified, getting to: --lang clj --custom-file-types repl

Additional context
Am interested in getting a PR together for this.

[borkdude]

Wouldn't it be easier for all parties / tooling if the transcriptor output just named these files .repl.clj?