reflow of doc string

src/tools/flow_control.py

@@ -48,9 +48,11 @@ def crc(message):
        processed.
     6. Repeat Steps 2 through 5 for the next 8–bit byte of the message. Continue doing this until all bytes have been processed.
     7. The final content of the CRC register is the CRC value.
-     8. When the CRC is placed into the message, its upper and lower bytes must be swapped as described below. 
+    8. When the CRC is placed into the message, its upper and lower bytes must
+       be swapped as described below.
     
-    Placing the CRC into the Message 
+    Placing the CRC into the Message:
+    =================================
     When the 16–bit CRC (two 8–bit bytes) is transmitted in the message, the low-order byte will be transmitted first, followed by the high-
     order byte.
     """