Allow dialect labels on audio files

[DJ-Saidez]

I was thinking, having several audio files available in a sentence is a great achievement (see #183), but I feel like having more immediately-accessible information visible on the sentence page, like dialect of the speaker, would be even more useful to be able to see differences between different recordings.

Maybe for now it could simply be some text that either the audio contributor or the admin initially adds, that then gets shown on every sentence that the contributor records. (Although this might get complicated if said contributor contributes audio in more than one language) Then maybe later on we can make it so that it works like tags, and we can organize audio based on these labels, so if we wanted to find specifically British English audio for example, we could use a tag for that.

Rough representation: Difference is I'd like the box to be expanded a bit to make room for the two lines to fit.

We could also use a similar method for any notes to add to the audio, such as specifying whether it's past or present tense, or even the mood of the way it's said, but that'd be a lot more manual since you'd have to deal with each individual sentence.