Conversion of old .sws worksheets using "sage -sws2rst" and "sage -n export"

[Matthias Koeppe]

Sage 9.2 removes the deprecated SageNB completely, as briefly noted in https://wiki.sagemath.org/ReleaseTours/sage-9.2#Cleaning

Would someone be able to add a few words on how to convert existing .sws files – preferably without having to refer people to an older version of Sage. 

There seem to be two routes -  "sage -n export" and "sage -sws2rst" (see https://trac.sagemath.org/ticket/28838 -- which needs review). Also, CoCalc seems to have another tool - https://doc.cocalc.com/sagews.html#conversion-utilities