v0.9.0 — dynamic message sign sensors
New message-sign sensors for the Montana provider. Montana's Iteris dms layer serves live sign text (e.g. "STAY ALIVE — DON'T DRINK & DRIVE"), so The 511 now creates a sensor per sign, nearest-to-home, capped by a new Maximum message signs option (default 25). South Carolina's dms layer is VSL-only (no text) and stays disabled.