0.12.0

This is a SUPER EXCITING release! With this, miette now has a full-featured
pretty-printer that can handle cause chains, snippets, help text, and lots
more!

Check out the serde_json
example
to see a "real-world" case!

This release also adds support for full thiserror-style format strings to
the help() diagnostic derive attribute!

We're rapidly approaching a 1.0-beta release. One more extra-fun treat left
and we can start stabilizing!

Features

• derive: format string support for help() (8fbad1b1)
• printer: lots of small improvements to printer (5fbcd530)
• reporter: fancy new reporter with unicode, colors, and multiline (#23) (d675334e)