* feat: [#21] stand up file sharing controls UI
* feat: [#21] implement basic file transfer
* feat: [#21] save transferred file
* feat: [#21] transfer file via WebTorrent
* fix: use external streamsaver assets
* feat: [#21] initiate download by receiver click
* fix: enable re-downloading of shared files
* feat: [#21] implement sharing of multiple files
* chore: enable offline development
* feat: cache torrents in IndexedDB
* feat: show alert when download is aborted
* feat: [#21] clean up torrent data when principal offerer rescinds it
* feat: clean up cached torrents on page unload
* feat: show file transfer progress
* fix: download files sequentially
* feat: clean up file transfers when leaving the room
* feat: clean up broken downloads upon leaving the page
* fix: allow download animation to complete
* feat: show tooltip for download button
* feat: make file transfers work in browser private modes
* feat: disable file share controls while creating offer
