Document Agglobus public transit for Bénac

Adds a dedicated transit-agglobus.md covering the TAD Sud on-demand
service Bénac relies on (booking, schedule, days, destinations), plus
the closest regular line (L3 via Saint-Pierre-de-Rivière), fares, where
to buy tickets, the Zenbus and TixiPASS apps, and SNCF/liO connections.
The transportation.md Public Transit stub now links to it.

content/getting-started/transportation.md

@@ -69,10 +69,16 @@ Our single car and bike are not necessarily available for communal use. Come wit
 - Helmets: *TBD*
 - Locks: *TBD*
 
-### Public Transit
-- **Nearest bus stop:** *TBD*
-- **Schedule:** *TBD*
-- **Routes:** *TBD*
+### Public Transit — Agglobus
+
+The local network is **[Agglobus](https://lagglobus.fr/)** (Pays Foix-Varilhes). No regular bus stops in Bénac — use the **Transport à la Demande (TAD)**, zone Sud, reserved by phone or online the day before.
+
+- **TAD reservation:** **05 32 74 18 15** (Mon–Fri 9h–12h / 14h–18h) or [online form](https://lagglobus.fr/reserver-son-transport-a-la-demande/) — by 17h the day before
+- **Days:** Tuesday, Wednesday, Friday, Saturday → Foix (and Pamiers on Wed/Sat)
+- **Fare:** 1 € le voyage / carnet 10 = 8 € / annual pass free under 26
+- **Closest regular stop:** Saint-Pierre-de-Rivière (~3–4 km) — Ligne 3 to Foix Parvis
+
+See [[transit-agglobus|Public Transit — Agglobus]] for the full guide (TAD schedule, line timetables, fares, where to buy tickets, apps).
 
 ### Hitchhiking
 - Hitchhiking is common practice in the region, highly utilized and recognized