Transposition detector v2

To add a transposition indicator in a song, simply add it as a single line starting either with + or - followed by the amount:

+2

Without specifying, the default transposition is always 0. Transpositions can be added anywhere between or before notation lines.

Additional formats also supported:

Transpose +3
transposition -3
Transposition is -3
Transpose by 3
*No Transposition*
-3 Octave 3 (+9)
-3 (transpose 6)