Sync resistor-color-duo

[mk-mxp]

• Run bin/configlet sync -u -e resistor-color-duo --yes --docs --filepaths --metadata --tests include (updates the Markdown files and maybe tests.toml)
  • metadata: unsynced: resistor-color-duo
• Drop strict types comments from test file and example code (these are useless)
  • Keep the comment in the students stub file. And the directive itself shall be in all PHP files, too.
• Add and sync test meta data to tests (uuid in DocBlocks / #TestDox())
• Add exercise to bin/auto-sync.txt to keep it in sync (keep the file alphabetically sorted)
• Decide on adding / adjusting / ordering test cases to match current problem specs
  • resistor-color-duo: missing 7 test cases
• If you wish, add your GitHub handle to the list of contributors in exercises/practice/resistor-color-duo/.meta/config.json

Do not redesign the student's interface or add test cases that would invalidate existing community solutions. These are extra tasks, which should be discussed in advance.