Recognize additional Dyalog APL file extensions

[ararslan]

Description

Dyalog APL uses a variety of file extensions in addition to .apl and .dyalog. The others are for specific kinds of definitions:

• .aplf for functions
• .apln for namespaces
• .aplc for classes
• .aplo for operators
• .apli for interfaces

At present, none of those extensions are recognized as APL by linguist; this PR adds them.

Checklist:

• [x] I am adding a new extension to a language.

  • [x] The new extension is used in hundreds of repositories on GitHub.com

    • Search results for each extension:
      • https://github.com/search?type=code&q=NOT+is%3Afork+path%3A*.aplf (11.2k)
      • https://github.com/search?type=code&q=NOT+is%3Afork+path%3A*.apln (244)
      • https://github.com/search?type=code&q=NOT+is%3Afork+path%3A*.aplc (240)
      • https://github.com/search?type=code&q=NOT+is%3Afork+path%3A*.aplo (330)
      • https://github.com/search?type=code&q=NOT+is%3Afork+path%3A*.apli (2, lol)
      • https://github.com/search?type=code&q=NOT+is%3Afork+path%3A*.apls (54)

  • [x] I have included a real-world usage sample for all extensions added in this PR:

    • Sample source(s):
      • .aplf: https://github.com/Co-dfns/Co-dfns/blob/f5ad1382e13dee0d56b7864a35e8fd740c2fec3a/ws/DISPLAY.aplf
      • .apln: https://github.com/nunezco2/quAPL/blob/23ccdfde79fcea30f51f8280f0197aca3377dc15/APLSource/circuit.apln
      • .aplc: https://github.com/aplteam/Tatin/blob/527049530026fe03c94b5a99cc2eb82029d2adcf/APLSource/Tester2.aplc
      • .aplo: https://github.com/rodrigogiraoserrao/ANNAPL/blob/4fbf53f7764e2b46ade62e398906af1c8ea1bf72/_Train.aplo
      • .apli: https://github.com/aplteam/ADOC/blob/3c23c88ef6a9d36aa5e7322ff26b5adeda1e20f4/APLSource/TestCases/testinterface.apli
      • .apls: https://github.com/Brian-ED/raylib-apl/blob/2a040bde6ba8a60bbee0e149c7f5904c8140268b/examples/3d-duck.apls
    • Sample license(s):

  • [ ] I have included a change to the heuristics to distinguish my language from others using the same extension.

    • Not applicable as these are only used by APL

[lildude]

This PR will be held back until all of the extensions you are adding each meet our usage requirements.

Rather than keeping this hanging around potentially forever, I recommend adding only those that meet our requirements. Users can always use an override for the others until usage is sufficient to be added.

[ararslan]

Ah sorry, I completely forgot about this. Looks like all but .apli and .apls meet the requirements you linked, at least as of a year ago. I meant to pare it down. I'll try to remember to do another PR with that.