The work regarding #17.
With 374928c we could merge a working version where the json is still missing a few fields, to iterate from there.
It is available via the normal stats endpoint by calling /json as the path.
Everything else will have the old text style.
Adds the --stats-hide-sensible-data flag (Docker: $TELEGRAM_STAT_HIDE_SENSIBLE_DATA=1), removing the bot token and the webhook url from the stats endpoint.
