Formalization of the extensions to the original Harte syntax used by ChoCo

[n28div]

Overall there are many chords in ChoCo whose syntax isn't expressed in the original Harte paper, such as hdim, sus2, min11, maj11, 11, min13, maj13, 13, 5, 6, 1/1.

A clear definition of how ChoCo extends the original set of shorthand, along with the degree they are composed of, solves possible ambiguities in the interpretation of chord labels.

[n28div]

By looking at choco/converters/validation/grammar-validation these appear to be the new shorthands and their respective components.

New shorthand	Components
augmaj7	1, 3, #​5, 7
aug7	1, 3, #​5, b7
dom7dim5	1, 3, b5, b7
minmaj9	1, b3, 5, 7, 9
augmaj9	1, 3, #​5, 7, 9
aug9	1, 3, #​5, b7, 9
hdim9	1, b3, b5, b7, 9
hdimmin9	1, b3, b5, b7, b9
dim9	1, b3, b5, bb7, 9
dimmin9	1, b3, b5, bb7, b9
11	1, 3, 5, b7, 9, 11
maj11	1, 3, 5, 7, 9, 11
minmaj11	1, b3, 5, 7, 9, 11
min11	1, b3, 5, b7, 9, 11
augmaj11	1, 3, #​5, 7, 9, 11
aug11	1, 3, #​5, b7, 9, 11
hdim11	1, b3, b5, b7, b9, 11
dim11	1, b3, b5, bb7, b9, b11
maj13	1, 3, 5, 7, 9, 11, 13
13	1, 3, 5, b7, 9, 11, 13
minmaj13	1, b3, 5, 7, 9, 11, 13
min13	1, b3, 5, b7, 9, 11, 13
augmaj13	1, 3, #​5, 7, 9, 11, 13
hdim13	1, b3, b5, b7, 9, 11, 13
sus2	1, 2, 5
7sus4	1, 4, 5, b7
power	1, 5
pedal	1