Feature request: option to disable enharmonic keys

[gerryster]

I like the app and it looks like a good way to learn Yew. However, as an armature jazz musician, I am very unlikely to encounter keys outside the circle of fifths that can be represented by more common keys. For example, the key of E# has the same notes as the key of F. It would be nice if there was an option to enable enharmonic keys similar to the existing option to enable double flats and sharps. For reference, the app produced E♯m7♭5. While this is an intellectually interesting example, it is a bit too theoretical for my current musical needs.