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/Setup/How-to-connect-Evennia-to-Twitter.md

@@ -76,13 +76,13 @@ class CmdTweet(Command):
  
         tlen = len(tweet)
         if tlen > 280:
-            caller.msg("Your tweet was %i chars long (max 280)." % tlen)
+            caller.msg(f"Your tweet was {tlen} chars long (max 280).")
             return
 
         # post the tweet        
         TWITTER_API.PostUpdate(tweet)
 
-        caller.msg("You tweeted:\n%s" % tweet)
+        caller.msg(f"You tweeted:\n{tweet}")
 ```
 
 Be sure to substitute your own actual API/Access keys and secrets in the appropriate places.