doc, util, console: clarify ambiguous docs
Add clarification to the documentation on util.format() and console.log() regarding how excessive arguments are treated when the first argument is a non-format string compared to when it is not a string at all.
Fixes: https://github.com/nodejs/node/issues/13908
Checklist
-
make -j4 test
(UNIX) -
documentation is changed or added -
commit message follows commit guidelines
Affected core subsystem(s)
doc, util, console