Automatically announce Svelte London stream

[ghostdevv]

trafficstars

For Svelte London it'd be nice to automatically ping events when the stream starts. I asked about this week in svelte and they said it'd be useful but maybe if it would post it 15 minutes prior, which then brings up the issue of if the stream has a delayed start. For now I'll just do it for Svelte London, and then we can revisit this in the future for other streams.