Treat sharrows as less effective than bike lanes

[ZMYaro]

From https://bostoncyclistsunion.slack.com/archives/C060R9LGMGS/p1760472016000859?thread_ts=1760459902.651059&cid=C060R9LGMGS:
Currently, the map treats sharrows as equivalent to paint-only bike lanes, per official LTS guidance. Consider changing that (with that deviation documented) since sharrows have since been shown to be less effective than previously hoped.