docs/changes: update for v0.5.5.

Author: whitequark

docs/changes.rst

@@ -9,7 +9,8 @@ Documentation for past releases
 
 Documentation for past releases of the Amaranth language and toolchain is available online:
 
-* `Amaranth 0.5.4 <https://amaranth-lang.org/docs/amaranth/v0.5.3/>`_
+* `Amaranth 0.5.5 <https://amaranth-lang.org/docs/amaranth/v0.5.5/>`_
+* `Amaranth 0.5.4 <https://amaranth-lang.org/docs/amaranth/v0.5.4/>`_
 * `Amaranth 0.5.3 <https://amaranth-lang.org/docs/amaranth/v0.5.3/>`_
 * `Amaranth 0.5.2 <https://amaranth-lang.org/docs/amaranth/v0.5.2/>`_
 * `Amaranth 0.5.1 <https://amaranth-lang.org/docs/amaranth/v0.5.1/>`_
@@ -23,6 +24,17 @@ Documentation for past releases of the Amaranth language and toolchain is availa
 * `Amaranth 0.3 <https://amaranth-lang.org/docs/amaranth/v0.3/>`_
 
 
+Version 0.5.5
+=============
+
+Standard library changes
+------------------------
+
+.. currentmodule:: amaranth.lib
+
+* Added: :class:`amaranth.lib.wiring.FlippedInterface` is hashable.
+
+
 Version 0.5.4
 =============