Clarify purpose of -e / --encoding option

[jeanas]

The frescobaldi command supports an -e / --encoding option to open files in an encoding other than UTF-8. I wonder why, since LilyPond supports UTF-8 encoded files exclusively, and no other encoding.

[fedelibre]

Maybe because Frescobaldi can also open .html or .tex files (mixed with lilypond code) and these files may have a different encoding? See for example #38 (well, opened in 2012). I guess that today any file should use UTF-8?

[jeanas]

Ah, yes, thank you, that explains it. (I agree though that in 2023, everything should just use UTF-8.)