Consider a separate repo for scribe-tool / scripts

[rhiaro]

This repo is massive because of all of the audio files, and it takes ages to fetch it the first time, and is pretty slow to fetch subsequent updates. When I just want to tweak scribe-tool, it's quite burdensome to download all of these audio files to my local machine.

I think it would be a suitable separation of concerns to keep this repo only for minutes/recordings, and have the 'plumbing' elsewhere. We could still keep a github pages scribe-tool page here (ie at w3c-ccg.github.io/meetings/scribe-tool) if that's desired by including the JS from another repo.