Add units to menu options which are not self-explanatory

[ahkneipp]

The "preroll" feature in particular could be either seconds or measures. Menu options which could be any of multiple units should have them labelled to avoid user confusion.

[kosua20]

Hello, that's a good point, thank you for your feedback! I've started to add extra labels in version 6.0 to clarify which units or range some values are using (timings, scalings, opacities...). Some remain quite arbitrary (based on internal parameters), but I'll see what I can do for these.