gh-48496: Added example and link to faq for UnboundLocalError in reference (GH-93068)

(cherry picked from commit f3db68e)

Co-authored-by: Stanley <46876382+slateny@users.noreply.github.com>

Author: miss-islington

Doc/faq/programming.rst

@@ -113,6 +113,8 @@ Yes.  The coding style required for standard library modules is documented as
 Core Language
 =============
 
+.. _faq-unboundlocalerror:
+
 Why am I getting an UnboundLocalError when the variable has a value?
 --------------------------------------------------------------------
 

Doc/reference/executionmodel.rst

@@ -128,6 +128,8 @@ lead to errors when a name is used within a block before it is bound.  This rule
 is subtle.  Python lacks declarations and allows name binding operations to
 occur anywhere within a code block.  The local variables of a code block can be
 determined by scanning the entire text of the block for name binding operations.
+See :ref:`the FAQ entry on UnboundLocalError <faq-unboundlocalerror>`
+for examples.
 
 If the :keyword:`global` statement occurs within a block, all uses of the names
 specified in the statement refer to the bindings of those names in the top-level