[Feature Request] Support for Brazilian/Latin chord notation 7M for major 7th chords

[naldobass]

Hi team,
I would like to request native support for the 7M suffix (e.g., C7M) when entering chord symbols.
In Brazilian and Latin American music notation, 7M is a widely used convention for major seventh chords (equivalent to maj7 or Δ).
Currently, typing 7M is not recognized properly for automatic formatting or playback. Adding 7M to the default chord dictionary/parser would greatly improve the workflow for users in regions using this standard without needing manual workaround.

e.g., if it's written F7M, it will play only the root. It completely ignores the seventh, not only the M qualifier. If it's FM7, or any other supported format, it plays all the chord notes correctly (F, A, C, E in this case).

Thank you for considering this addition!

Ronaldo.