Feat/admin style

[nateconley]

Description of the Change

• Changes style of the admin settings page
• Removes IE-specific stylesheet
• Changes "MailChimp" to "Mailchimp"
• Updates markup for accessibility (labels on inputs, etc)

Closes #6

How to test the Change

(From #6) Creating the below checklist of items to update per the Figma updates from Eddie Shrake:

• Update header in Settings page to Freddie icon (40x40), bg color: white (#FFFFFF), border-top: 2px (#FFE01B), title as "Mailchimp List Subscribe Form" in #241C15
• Change ALL buttons and links to Kale (#007C89)
• Change ALL instances of "MailChimp" to "Mailchimp" (note I think this is likely already done in Update/dotorg standards #14 but worth double checking on the Settings page in any case)
• Change ALL section backgrounds and borders to Squash (#FBEECA)
• Change ALL section titles to Black/Peppercorn (#241C15)

Changelog Entry

Changed - Admin styles to match comp
Deprecated - Removes IE-specific admin stylesheet
Fixed - Accessibility for admin settings page

Credits

@nateconley

Checklist:

• I agree to follow this project's Code of Conduct.
• I have updated the documentation accordingly. - n/a
• I have added tests to cover my change.
• All new and existing tests pass.

[dkotter]

Couple additional notes:

There's some links on the main setup page that aren't the right color yet:

If I try and connect with no API key or an invalid key, the error message needs more spacing (and maybe change to a red color, though that's my opinion):

[dkotter]

One other thing I'm seeing is the Powered by WordPress footer link is overlapping the left-side nav bar when on the initial settings screen (seems to be fine once you're connected). I'm guessing there's some markup or styling issues in what is output on this settings screen that's causing this:

[nateconley]

@dkotter I have addressed all of your comments and this is ready for re-review. Thank you!