manual/workflow-tips: simplify the basic workflow (and explain the why) (#48319)
I came upon this piece of documentation again after seeing this post:
https://discourse.julialang.org/t/how-to-clear-variables-and-or-whole-work-space/10149/21?u=tfiers
("How to clear variables and/or whole work space?" → "Work in a module")
This small addendum to the Worfklow Tips section of the manual answers
"but why should I bother making that module";
basically putting the gist of that discourse thread in the
documentation, where more people might see it.