- add guide to documentation and example files to repository to run coturn alongside PairDrop via Docker Compose

- enable TURN over TLS
- modified the .gitignore to ignore files with user-data
- should fix #105
- partly cherry-picked from #106

Co-authored-by: xundeenergie <xundeenergie@users.noreply.github.com>

.gitignore

@@ -3,3 +3,6 @@ node_modules
 fqdn.env
 /docker/certs
 qrcode-svg/
+turnserver.conf
+rtc_config.json
+ssl/