Make settings page top-level

[nateconley]

Description of the Change

• Moves settings to top-level menu page
• Adds "Freddie" icon from files provided to us
  • Followed ElasticPress style of 84.66% width SVG and inline base64 encoded

Closes #8

How to test the Change

• Settings save as expected
• Settings styles are maintained

Changelog Entry

Changed - Moves settings page to top-level

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. - N/A
• All new and existing tests pass.