Document additional panic codes.

docs/reference/control/assert.md

@@ -0,0 +1,29 @@
+# assert
+
+Stop the program if the assertion condition is false.
+
+```sig
+control.assert(false)
+```
+
+You can insist that your program will stop at an assert block if a certain condition you check is false. The error number in the assert is written to the serial port with a failure message.
+
+## Parameters
+
+* **cond**: a [boolean](/types/boolean) where true means everything is ok or false which means, stop the program!
+* **msg**: an optional [string](/types/string) with a message describing the failed assertion.
+
+## Example
+
+Stop the program if a sensor connected to pin `P0` sends a low (`0`) signal.
+
+```blocks
+basic.forever(() => {
+    control.assert(pins.digitalReadPin(DigitalPin.P0) == 1)
+    basic.pause(1000)
+})
+```
+
+## See also
+
+[panic](/reference/control/panic)