docs: Fix location of AF3_EXCLUDED_LIGANDS_REGEX

A secondary issue here is that the cross-link to the Python file (in this line and the previous) does not work on the rendered version at https://rosettacommons.github.io/atomworks/latest/mirrors.html (Not sure if there's a good fix for that.)

Author: roccomoretti

docs/mirrors.rst

@@ -82,7 +82,7 @@ Next we need to use the metadata to configure a dataset that we would like to sa
 Here's a simple example that:
 
 * Filters to D-polypeptide and L-polypeptide chains only (`POLYPEPTIDE_D` and `POLYPEPTIDE_L` -- to include additional chain types, replace the lists with the appropriate IDs (see [mapping](./src/atomworks/enums.py#L31-L45) in comments).
-* Excludes ligands in the AF3 list of excluded ligands, available at [`atomworks.io.constants.AF3_EXCLUDED_LIGANDS_REGEX`](./src/atomworks/constants.py#L350).
+* Excludes ligands in the AF3 list of excluded ligands, available at [`atomworks.constants.AF3_EXCLUDED_LIGANDS_REGEX`](./src/atomworks/constants.py#L350).
 
 .. code-block:: yaml