gh-85583: Add f-string index in tutorial/inputoutput.rst (GH-21681)

* bpo-41411 fstring index in tutorial/inputoutput

To assist in searching for fstrings I have added an index

* Add newline

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Co-authored-by: Adam Turner <[email protected]>
Co-authored-by: Carol Willing <[email protected]>

Author: 3 people

Doc/tutorial/inputoutput.rst

@@ -100,6 +100,13 @@ yet another way to substitute values into strings, using placeholders like
 ``$x`` and replacing them with values from a dictionary, but offers much less
 control of the formatting.
 
+.. index::
+   single: formatted string literal
+   single: interpolated string literal
+   single: string; formatted literal
+   single: string; interpolated literal
+   single: f-string
+   single: fstring
 
 .. _tut-f-strings: