v0.8.0 Assistants

This release introduces compo-sable assistants! These allow you to write general purpose or app specific assistants in any language and chain them together. See below for more info (documentation is on its way :-))

What's Changed

• Generalised assistants by @richiejp in #38
• Nix and Go mod updates by @richiejp in #39

Full Changelog: v0.7.2...v0.8.0