Adding more sonification options

[ceb8]

This PR adds a few more user controls to the series sonification (relevant to issue https://github.com/spacetelescope/astronify/issues/7):

• Note duration: how long each individual tone is
• Note spacing: the spacing between notes, i.e. the time in seconds that corresponds to the median difference between time bins (mentioned in issue https://github.com/spacetelescope/astronify/issues/8)
• Invert: Higher data values (usually flux) can be made to correspond to lower pitches

Also I fixed (hopefully) the way I took the stretched/scaled data values (now floats 0-1) to the pitch values which was buggy. However I am still not confident in what I am doing. @scfleming and @theresadower if you could take a look (lines 113-116 in the pitch mapping function) I would really appreciate it.

[ceb8]

Closing this because we switched the default branch from master to main.