v6.7.0

What's Changed

• docs(design-guidelines): Adds new AI icons and updates guidance. by @edonehoo in #836
• fix(MessageBar): removed gradient and thinking animation by @thatblindgeye in #845
• fix(ChatbotFootnote): updated verbiage and combined examples by @thatblindgeye in #846
• fix(ChatbotToggle): Adjust icon by @rebeccaalpert in #851
• feat(Chatbot): applied glass and felt tokens by @thatblindgeye in #849
• feat(Message): add default bot message avatar by @kmcfaul in #850

Full Changelog: v6.6.0...v6.7.0