[Improvement suggestion] add leading zeroes to chapter numbers in output file name in order to have correct file system ordering.

[dreirund]

Ahoj,

when I use the script, the resulting output file names are numbered without leading zeroes, leading to sorting issues using normal file system tools (like ls -1):

'10 - Homo qui vigeas.opus'
'11 - In terra sumus rex.opus'
'12 - Licet eger II.opus'
'13 - Ludus de Passione.opus'
'14 - Nomen a solempnibus II.opus'
'15 - Procurans odium II.opus'
'16 - Sanctissima et glorissima.opus'
'17 - Si vocatus ad nuptias.opus'
'18 - Clauso Chronos.opus'
'19 - Dulce solum natalis patrie.opus'
'1 - Ave Maria gratia plena.opus'
'20 - Exiit diluculo rustica puella.opus'
'21 - Ich was ein chint so wolgetan.opus'
'22 - In Gedeonis area.opus'
'23 - Iste mundus furibundus.opus'
'24 - Licet eger.opus'
'25 - Michi confer venditor I.opus'
'26 - Olim sudor Herculis.opus'
'27 - Plaintes Mariales du Jeu de la Passion- Axe Phebus aureo.opus'
'28 - Procurans odium I.opus'
'29 - Sic mea fata canendo solo.opus'
'2 - Ave domina mundi.opus'
'30 - Tempus est Iocundum.opus'
[...]

I hereby suggest that the resulting split files are named with as many leading zeroes as needed, so that every number has the same amount of digits; and minimum two digits (which corresponds to what usually is found "in the wild"), so that my example would look like:

01 - Ave Maria gratia plena.opus
02 - Ave domina mundi.opus
[...]
'10 - Homo qui vigeas.opus'
'11 - In terra sumus rex.opus'
[...]

Regards!