Redesign and simplify nav

[tylersticka]

Nav changes include:

• Moved border color to background instead
• Inverted active/inactive colors to emphasize active page
• Tweaked branding area to allow for text "logo" as default
• Resolved weird issues related to @nest rules no longer working
• Made nav expand icon smaller now that I understand how <polyline> works
• Misc. simplifications

  Before

  Narrow

Wide

After

Narrow

Wide

---

@erikjung @mrgerardorodriguez @nicolemors @saralohr

Fixes #9, Fixes #12

[gerardo-rodriguez]

Love it! 👍