Add Maple language

[Remenod]

Add Maple language support with .maple and .mpl extension

Description

This PR adds support for the Maple programming language to Linguist. Maple is a symbolic and numeric computing environment widely used for mathematical computation, algorithm development, and teaching. It provides features for algebraic manipulation, calculus, linear algebra, and plotting, and supports procedural and object-oriented programming constructs.

Checklist:

• I am adding a new language.
  • The extension of the new language 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*.mpl+with+OR+end+OR+:=+OR+proc
      • https://github.com/search?type=code&q=NOT+is%3Afork+path%3A*.maple
  • I have included a real-world usage sample for all extensions added in this PR:
    • Sample source(s):
      • https://github.com/rpiRobotics/subproblem-polynomial
      • https://github.com/afni/afni/
    • Sample license(s): BSD-3-Clause, Public domain
    • Notes: Some of the sample code was AI-generated. These samples provide small, self-contained Maple scripts demonstrating basic algorithms, loops, object-oriented functions, and standard library usage.
  • I have included a syntax highlighting grammar: https://github.com/yu961549745/VSCodeHighlightForMaple
  • I have added a color
    • Hex value: #00476D
    • Rationale: Matches the color used in the official Maple logo
  • I have updated the heuristics to distinguish my language from others using the same extension.

[lildude]

Some of your samples are not real-world examples of the usage of the language and appear to be contrived or illustrations of the language. Please remove or replace those are that aren't with real-world usage examples.