Warn if title is empty

[HW-Jarausch]

If one forgets to specify a Title, any entries are lost without any warning.
Please add such a warning and ask the user to confirm discarding any entries done so far.

[damionx7]

Hey, the note file is saved with a default filename. I will add a warning for this though,

[nutpantz]

It would be nice if the default filename was renamed with an index ie default01. Default02 automatically if the filename exists

[damionx7]

The default index updates automatically. First file is 'Unititled', next file will be 'Untitled_1'.