Nav state

[outofambit]

• refactors the state management of the main nav links and jump to links panels to:
  • on mobile: make it such that both panels cannot be open at the same time
  • on desktop: at least one panel must be open at all times
  • watches for viewport changes require switching from one behavior to another

this introduces a bit more javascript to the app, but i think its unavoidable to get the behavior right here