[802.3_YANG] Maximum line length of YANG modules
IETF YANG modules lines are restricted to 69 characters. This is because
they are embedded into RFCS (max 72 characters/line), and the module
ends up being indented by 3 spaces in the RFC.
For my updates to the 802.3 Ethernet YANG modules, I am also currently
formatting the maximum line length to 69 characters, but I don't know if
IEEE uses a higher limit for MIBs/YANG modules. If I should be using a
different, higher limit, then please can you let me know, and I'll
reformat the descriptions accordingly.