feat: match updated designs for button

[ericdouglaspratt]

🔗 Linked issue

• n/a

❓ Type of change

• 📖 Documentation (updates to the documentation or readme)
• 🐞 Bug fix (a non-breaking change that fixes an issue)
• 👌 Enhancement (improving an existing functionality like performance)
• ✨ New feature (a non-breaking change that adds functionality)
• ⚠️ Breaking change (fix or feature that would cause existing functionality to change)

📚 Description

• Matches the updated Figma designs for buttons, especially the 1px border rather than 2px
• All focus states will only appear on :focus-visible instead of :focus, meaning you won't see them showing up unnecessarily on mouse/tap interaction, but you will see them on keyboard tabbing, which is exactly when Chrome shows its default focus outlines
• Greatly simplified the Button docs page with more straightforward examples to copy from
• Gave non-inline link buttons a darker active state and the press-down animation to match their siblings
• Removed the dark-bg button variant's glow shadow

🥼 Testing

• Tested locally

🧐 Feedback Requested / Focus Areas

• Overall

📝 Checklist

• I have linked an issue or discussion.
• I have updated the documentation accordingly.
• I have documented testing approach

[nathanielwarner]

Looks pretty good, no obvious issues with the code! I do have one concern with the changes in focus state- the dark background examples are now harder to see when navigating by keyboard, as compared to the current implementation. That's because the light blue outline is no longer present on focus. Were these changes part of the scope of the design request?