issue #2243 -- prefer f-strings over %-interpolation

edited docs to prefer f-strings, then str.format(), and remove %-interpolation

additional ad-hoc documentation fixes, as opportunities seen:
- replace Built-In Function (BIF) "min" variable with "mins"
- prefer BIF str(var) over "%s" % var
- reformat some code examples to clarify multiple args passed to functions
- change some single-quote strings to double-quotes for consistency
- fix mismatched parens

misc edits:
- add .vscode/ to gitignore

docs/source/Concepts/Messagepath.md

@@ -145,7 +145,7 @@ Here are some examples
 
 ```python
     msg("Hello!")   # using the 'text' outputfunc
-    msg(prompt="HP:%i, SP: %i, MP: %i" % (HP, SP, MP))
+    msg(prompt=f"HP: {HP}, SP: {SP}, MP: {MP}")
     msg(mycommand=((1,2,3,4), {"foo": "bar"})
 
 ```