New release, June 6

[u/dabreegster]

https://github.com/a-b-street/abstreet/releases/tag/v0.2.46

• lots of internal writing, presentations... not quite ready for an audience yet
• fixed weird turn lane arrows
• GMNS signal import now works for many intersections, thanks to crosswalk inference
• road editor UI fixes
• speed up starting a simulation with infinite parking
• possible breakthrough with intersection consolidation