fix: add util module, w/ model_transaction_query()

just a basic implementation, will have to improve later

docs/conf.py

@@ -27,6 +27,7 @@ templates_path = ["_templates"]
 exclude_patterns = ["_build", "Thumbs.db", ".DS_Store"]
 
 intersphinx_mapping = {
+    "sqlalchemy": ("http://docs.sqlalchemy.org/en/latest/", None),
     "sqlalchemy-continuum": (
         "https://sqlalchemy-continuum.readthedocs.io/en/latest/",
         None,