Itinerary improvements

[graue]

While a basic version of the detailed itinerary is done, there's a lot left to improve:

(some of these may be worth splitting into separate issues!)

Tier 1: before considering the feature done

• fix visual glitch in timeline when an itinerary row wraps #148
• improve design of single-step view (and add prev/next arrow buttons) #396
• show final destination head-sign below transit boarding info (e.g. "Towards Antioch") #129
• make board/alight stops from transit legs clickable, zooming map to those stops #189

Tier 2: nice-to-haves

• preserve scroll position when going back from single-step view to full itinerary #218
• play with showing more transit stops
  • more-vert icon to represent default-hidden ones
  • default: show 1 or 2 additional stops after boarding stop and/or before alighting stop
  • button (looks like a link? blue text?) to expand and reveal all stops
• add mock's light gray line below each step #149
• below each bike step, summarize the bike infra in that step #170
• Label steep hills in instructions #173

Original mock for reference

[graue]

@abhumbla see above under Tier 2 for ideas on expanding transit stops

you can find the referenced icon at https://iconoir.com/

[graue]

These are all done!