Allow more 'parts of song' heading options in Theme settings
Currently, the 'Theme' settings are restricted to 'Chordle Classic', 'Nighttime', and 'Custom Theme backgrounds.
The headings that are allowable are a bit limited - apparently only those listed (Bridge, Verse, Chorus, Pre-Chorus, Intro, Ending, and Instrumental) can be used or recognized by the program display.
There are many common terms for a song's parts. For example, in addition to 'Ending', Outtro and Tag are also commonly used. In addition to 'Instrumental', 'Solo' could also be allowed.