Speaker notes for title page.

[mainrs]

Right now, the only way to include speaker notes for the title page is to add them to the extra field. I found this to be quite unintuitive. My first approach was to use title-page(...)[pdfpc.speaker-notes()], which didn't work.

Maybe add a specified field like notes or similar that just expects the speaker-notes content? It makes the intention and usage clear.

I am using the Metropolis theme.