* enables titlefetching per-channel (avoids unwanted channels in case of botloop)
* could also be `config config` or `config network NETWORKNAME` to do globally or per-network, but risk of accidental botloop
* sets user-agent to "Limnoria UrlPreviewBot" instead of ['Mozilla/5.0 (compatible; utils.web python module)' from 2005](https://github.com/ProgVal/Limnoria/blame/2990fcd302afdc6a3b741594017c3959fd5da2fd/src/utils/web.py#L120)
* I have heard that it's bad to pretend to be something you aren't and Twitter will only give you HTMl `<title>`s if your user-agent contains `UrlPreviewBot`