Add backticks around *args in docstring.

[ntouran]

Having parameter docs named *args and **kwargs in a docstring was causing downstream errors in sphinx where sphinx thought it was going to be an italic block with a following asterisk or two.

docutils recommends that things like this should be liberals literals:

https://docutils.sourceforge.io/docs/ref/rst/restructuredtext.html#inline-markup-recognition-rules

Fixes https://github.com/terrapower/armi/issues/481

[SimplyKnownAsG]

liberals to the rescue :-)