Add support for Ruby Option Lists

[spenserblack]

This adds support for files that contain command-line options used by RSpec and Yard.

Description

• .rspec documentation
• .yardopts documentation

Checklist:

• I am adding a new extension filename to a language.
  • The new extension filename is used in hundreds of repositories on GitHub.com
    • Search results for each extension:
      • .rspec (2.6k)
      • .yardopts (1.8k)
  • I have included a real-world usage sample for all extensions added in this PR:
    • Sample source(s):
      • .rspec
      • .yardopts
    • Sample license(s):
      • MIT (.rspec)
      • MIT (.yardopts)
  • I have included a change to the heuristics to distinguish my language from others using the same extension. No other uses of these filenames AFAIK