Update AUTHORS.rst and CHANGES.rst

Author: gastmaier

AUTHORS.rst

@@ -72,6 +72,7 @@ Contributors
 * Joel Wurtz -- cellspanning support in LaTeX
 * John Waltman -- Texinfo builder
 * Jon Dufresne -- modernisation
+* Jorge Marques -- unique ids in singlehtml
 * Josip Dzolonga -- coverage builder
 * Juan Luis Cano Rodríguez -- new tutorial (2021)
 * Julien Palard -- Colspan and rowspan in text builder

CHANGES.rst

@@ -66,6 +66,11 @@ Features added
   Patch by Adam Turner.
 * #13805: LaTeX: add support for ``fontawesome7`` package.
   Patch by Jean-François B.
+* #13739: singlehtml builder: append the docname to ids with format
+  ``/<docname>/#<id>``, to ensure uniqueness. For example, ``id3`` becomes
+  ``/path/to/doc/#id3``. This is a breaking change since it alters the format
+  of the ids in both the content body and the toctree. Fixes toctree
+  refid format ``document-<docname>`` that did not match the id in the body.
 
 Bugs fixed
 ----------