Added info to changelog and docs

Author: Daraan

CHANGELOG.md

@@ -12,6 +12,8 @@
 - Fix bug where a subscripted `TypeAliasType` instance did not have all
   attributes of the original `TypeAliasType` instance on older Python versions.
   Patch by [Daraan](https://github.com/Daraan) and Alex Waygood.
+- Extended the Concatenate backport for Python 3.9 and 3.10 to now accept
+  ellipsis as an argument. Patch by [Daraan](https://github.com/Daraan).
 
 # Release 4.12.2 (June 7, 2024)
 

doc/index.rst

@@ -178,7 +178,7 @@ Special typing primitives
    See :py:data:`typing.Concatenate` and :pep:`612`. In ``typing`` since 3.10.
 
    The backport does not support certain operations involving ``...`` as
-   a parameter; see :issue:`48` and :issue:`110` for details.
+   a parameter; see :pr:`442`, :issue:`48` and :issue:`110` for details.
 
 .. data:: Final