Update button component previews

[jenniferthibault]

Summary

• Updates the button component based on criteria set in Adjust buttons component so that it's up to date and accurate #57
  • Basic: Remove active state. The active state will be shown through the toggle component
  • Basic: Add more spacing between buttons so that they don't look so much like toggles
  • Icons: Show each button in just one color—color changes can be determined by the basic tab, and this will cut down clutter
  • Icons: Add dropdown buttons. These examples were missing from the components
  • Sizes: Remove the colored background slab to be consistent
• Adds additional toggle button examples discovered during research

Notes for review

• If Adds notes for first half of components audited #54 is merged before this PR, redirect this toward the master branch and any merge conflicts will need to be resolved.
• The "dropdown" functionality does not work in the examples I included of dropdown buttons with icons, and I'm not quite sure why. I'd like to merge without the functionality, since it's still useful in this state, and file a separate issue for making them work as examples.
• Resolves Adjust buttons component so that it's up to date and accurate #57

[xtine]

Which are the "dropdown buttons with icons?" I can see what is missing for them to work.

[xtine]

Looks good! 👍

[jenniferthibault]

If you want to add a commit to make the dropdown buttons work, that would be amazing!

I included three examples in the buttons with icons section:

• Subscribe
• Download
• Add to calendar

The options that appear in the dropdown lists can get taked from the real examples of them in use on the calendar: https://www.fec.gov/calendar/

[xtine]

Hooked up the button icon dropdowns:

Bonus: got the favicon working!

[jenniferthibault]

Woohoo! Thanks @xtine, I ran your additions locally and they look good, so since you approved the review, I'll merge 🔆