[Doc] Use intersphinx and update entrypoints docs (#5125)

docs/source/conf.py

@@ -80,7 +80,7 @@ def setup(app):
     generate_examples()
 
 
-# Mock out external dependencies here.
+# Mock out external dependencies here, otherwise the autodoc pages may be blank.
 autodoc_mock_imports = [
     "cpuinfo",
     "torch",
@@ -115,4 +115,15 @@ class MockedClassDocumenter(autodoc.ClassDocumenter):
 
 autodoc.ClassDocumenter = MockedClassDocumenter
 
+intersphinx_mapping = {
+    'python': ('https://docs.python.org/3', None),
+    'typing_extensions':
+    ('https://typing-extensions.readthedocs.io/en/latest', None),
+    'numpy': ('https://numpy.org/doc/stable', None),
+    'torch': ('https://pytorch.org/docs/stable', None),
+    'psutil': ('https://psutil.readthedocs.io/en/stable', None),
+}
+
+autodoc_preserve_defaults = True
+
 navigation_with_keys = False