Rename Red Knot (#17820)

crates/ty_python_semantic/resources/mdtest/shadowing/function.md

@@ -0,0 +1,53 @@
+# Function shadowing
+
+## Parameter
+
+Parameter `x` of type `str` is shadowed and reassigned with a new `int` value inside the function.
+No diagnostics should be generated.
+
+```py
+def f(x: str):
+    x: int = int(x)
+```
+
+## Implicit error
+
+```py
+def f(): ...
+
+f = 1  # error: "Implicit shadowing of function `f`"
+```
+
+## Explicit shadowing
+
+```py
+def f(): ...
+
+f: int = 1
+```
+
+## Explicit shadowing involving `def` statements
+
+Since a `def` statement is a declaration, one `def` can shadow another `def`, or shadow a previous
+non-`def` declaration, without error.
+
+```py
+f = 1
+reveal_type(f)  # revealed: Literal[1]
+
+def f(): ...
+
+reveal_type(f)  # revealed: def f() -> Unknown
+
+def f(x: int) -> int:
+    raise NotImplementedError
+
+reveal_type(f)  # revealed: def f(x: int) -> int
+
+f: int = 1
+reveal_type(f)  # revealed: Literal[1]
+
+def f(): ...
+
+reveal_type(f)  # revealed: def f() -> Unknown
+```