docs: init glossary (#33995)

docs/concepts/glossary.md

@@ -1,8 +1,9 @@
 # openpilot glossary
 
-* **route**:
+* **onroad**: openpilot's system state while ignition is on
+* **offroad**: openpilot's system state while ignition is off
+* **route**: a route is a recording of an onroad session
 * **segment**: routes are split into one minute chunks called segments.
-* **panda**: this is . See the repo.
-* **onroad**:
-* **offroad**:
-* **comma 3X**:
+* **comma connect**: the web viewer for all your routes; check it out at [connect.comma.ai](https://connect.comma.ai).
+* **panda**: this is the secondary processor on the device that implements the functional safety and directly talks to the car over CAN. See the [panda repo](https://github.com/commaai/panda).
+* **comma 3X**: the latest hardware by comma.ai for running openpilot. more info at [comma.ai/shop](https://comma.ai/shop).

mkdocs.yml

@@ -18,10 +18,12 @@ nav:
   - How-to:
     - Turn the speed blue: how-to/turn-the-speed-blue.md
     - Connect to a comma 3/3X: how-to/connect-to-comma.md
+    # - Make your first pull request: how-to/make-first-pr.md
     #- Replay a drive: how-to/replay-a-drive.md
   - Concepts:
     - Logs: concepts/logs.md
     - Safety: concepts/safety.md
+    - Glossary: concepts/glossary.md
   - Car Porting:
     - What is a car port?: car-porting/what-is-a-car-port.md
     - Porting a car brand: car-porting/brand-port.md