docs(conf): Add pydantic intersphinx mapping

why: Model classes inherit from pydantic.BaseModel but "Bases: BaseModel"
wasn't linking to pydantic docs.
what:
- Add pydantic to intersphinx_mapping (https://docs.pydantic.dev/latest/)
- "Bases: BaseModel" on all model pages now links to pydantic API docs

Author: tony

docs/conf.py

@@ -202,6 +202,7 @@
     "python": ("https://docs.python.org/", None),
     "pytest": ("https://docs.pytest.org/en/stable/", None),
     "libtmux": ("https://libtmux.git-pull.com/", None),
+    "pydantic": ("https://docs.pydantic.dev/latest/", None),
 }