docs: add concepts section

docs/concepts/glossary.md

@@ -0,0 +1,8 @@
+# openpilot glossary
+
+* **route**:
+* **segment**: routes are split into one minute chunks called segments.
+* **panda**: this is . See the repo.
+* **onroad**:
+* **offroad**:
+* **comma 3X**:

docs/concepts/logs.md

@@ -1,10 +1,8 @@
-# loggerd
+# Logging
 
 openpilot records routes in one minute chunks called segments. A route starts on the rising edge of ignition and ends on the falling edge.
 
-Check out our [python library](https://github.com/commaai/openpilot/blob/master/tools/lib/logreader.py) for reading openpilot logs. Also checkout our [tools](https://github.com/commaai/openpilot/tree/master/tools) to replay and view your data. These are the same tools we use to debug and develop openpilot.
-
-## log types
+Check out our [Python library](https://github.com/commaai/openpilot/blob/master/tools/lib/logreader.py) for reading openpilot logs. Also checkout our [tools](https://github.com/commaai/openpilot/tree/master/tools) to replay and view your data. These are the same tools we use to debug and develop openpilot.
 
 For each segment, openpilot records the following log types:
 
@@ -15,9 +13,10 @@ rlogs contain all the messages passed amongst openpilot's processes. See [cereal
 ## {f,e,d}camera.hevc
 
 Each camera stream is H.265 encoded and written to its respective file.
-* fcamera.hevc is the road camera
-* ecamera.hevc is the wide road camera
-* dcamera.hevc is the driver camera
+
+* `fcamera.hevc` is the road camera
+* `ecamera.hevc` is the wide road camera
+* `dcamera.hevc` is the driver camera
 
 ## qlog.bz2 & qcamera.ts
 

docs/concepts/safety.md

@@ -0,0 +1 @@
+../SAFETY.md

docs/how-to/replay-a-drive.md

@@ -0,0 +1,14 @@
+# Replay
+
+Replaying is a critical tool for openpilot development and debugging.
+
+## Replaying a route
+*Hardware required: none*
+
+Just run `tools/replay/replay --demo`.
+
+## Replaying CAN data
+*Hardware required: jungle and comma 3/3X*
+
+1. Connect your PC to a jungle.
+2.

mkdocs.yml

@@ -16,6 +16,10 @@ 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
+    #- Replay a drive: how-to/replay-a-drive.md
+  - Concepts:
+    - Logs: concepts/logs.md
+    - Safety: concepts/safety.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