Add documentation

sohstationviewer/model/reftek/reftek_data/header.py

@@ -55,6 +55,12 @@ def parse_rt130_time(year: int, time_bytes: bytes) -> UTCDateTime:
 
 
 def get_rt130_packet_header(rt130_packet: bytes) -> PacketHeader:
+    """
+    Get the packet header stored in the first 16 bits of an RT130 packet.
+
+    :param rt130_packet: the RT130 packet to process
+    :return: a PacketHeader object containing the header of rt130_packet
+    """
     try:
         # Because RT130 data is always big-endian, it is more convenient to
         # use str.decode() than the unpacker.