Mapping of globs to languages

[passcod]

It would be useful to be able to map path globs to supported languages, for cases where tracey's internal list of the extensions doesn't cut it. Motivating examples:

• extension-less shebanged executables ("scripts"), where bin/foo, bin/bar, bin/baz might all be bash, but will be completely ignored by tracey. In some cases it might be appropriate to rename those to bin/foo.sh or something, but in others it might not. Plus, it doesn't have to be bash: their shebang might be #!/usr/bin/env node or cargo-script...
• Tool files that need to be at particular filenames but are written in a covered language.
• Legit extensions for the language that aren't covered by tracey's hardcoded list.

The proposal is for a mapping of globs to language tags (essentially the inverse of "Option B" from #9) which is specified to be "first match wins". Then the internal extension mapping would append to the configured list. For example:

@schema {id crate:tracey-config@1, cli tracey}

specs (
    {
        name example
        include (docs/spec/**/*.md)
        impls (
            {
                name main
                include (
                    installer/**/*.rs
                    admin/**/*.pl
                    bin/*
                )
                language (
                	bin/foobar Perl
                	bin/* Shell
                )
            }
        )
    }
)

Implementation-wise, this would probably involve an enum of supported languages, that is figured from this mapping for each path, and then used throughout; incidentally I've noticed tracey contains at least three different places where it maps extensions to filetypes...