Doc: Add link of GNU Readline library to interpreter tutorial (GH-16152)

Doc/tutorial/interpreter.rst

@@ -34,13 +34,14 @@ status.  If that doesn't work, you can exit the interpreter by typing the
 following command: ``quit()``.
 
 The interpreter's line-editing features include interactive editing, history
-substitution and code completion on systems that support readline.  Perhaps the
-quickest check to see whether command line editing is supported is typing
-:kbd:`Control-P` to the first Python prompt you get.  If it beeps, you have command
-line editing; see Appendix :ref:`tut-interacting` for an introduction to the
-keys.  If nothing appears to happen, or if ``^P`` is echoed, command line
-editing isn't available; you'll only be able to use backspace to remove
-characters from the current line.
+substitution and code completion on systems that support the `GNU Readline
+<https://tiswww.case.edu/php/chet/readline/rltop.html>`_ library.
+Perhaps the quickest check to see whether command line editing is supported is
+typing :kbd:`Control-P` to the first Python prompt you get.  If it beeps, you
+have command line editing; see Appendix :ref:`tut-interacting` for an
+introduction to the keys.  If nothing appears to happen, or if ``^P`` is
+echoed, command line editing isn't available; you'll only be able to use
+backspace to remove characters from the current line.
 
 The interpreter operates somewhat like the Unix shell: when called with standard
 input connected to a tty device, it reads and executes commands interactively;