Add configurable DS18B20 temperature probe support

docs/SERIAL_COMMANDS.md

@@ -414,3 +414,41 @@ Attempt STA WiFi connection using saved networks by priority.
 AP remains available at:
 
     192.168.4.1
+
+---
+
+# Temperature Probe Setup
+
+## scan temps
+
+Scans the DS18B20 1-Wire bus and prints detected sensor addresses.
+
+Example:
+
+    scan temps
+
+## assign temp <slot> <number>
+
+Assigns a detected physical sensor to a configured temp slot.
+
+Example:
+
+    assign temp 1 1
+    assign temp 2 2
+    save
+
+## clear temp <slot>
+
+Clears and disables a configured temp slot.
+
+Example:
+
+    clear temp 1
+
+Wiring reminder:
+
+    DS18B20 red    -> 3.3V
+    DS18B20 black  -> GND
+    DS18B20 yellow -> GPIO4
+
+A single 4.7k resistor is required between 3.3V and GPIO4/data.