Option to reduce Slack real estate

[djsmith42]

Sentry errors currently look like this for my project:

It would be nice if there was an option to use less vertical real estate like this:

Looking at the code for the plugin, it seems like this would be doable by omitting all the fields in the SlackPlugin.notify() method based on a new BooleanField option called verbose that could be added.

Does this sound like a reasonable request?