Started on DS18B20 and PMS5003

Didn't realise DS18B20 was 1-Wire

Will probably just find a library for that one - can't be arsed
doing more bit banging

components/ds18b20/ds18b20.h

@@ -0,0 +1,7 @@
+#pragma once
+
+int ds18b20_read(void);
+
+typedef enum {
+  DS18B20_OK,
+} ds18b20_error;