Fix typos in docs

Author: desert

docs/usage.rst

@@ -123,7 +123,7 @@ Any :class:`marshmallow.Schema.Meta` value is accepted in the meta dict. For exa
     class A:
         x: int
 
-    schema = desert.schema_class(A, meta={"unknwown": marshmallow.EXCLUDE})()
+    schema = desert.schema_class(A, meta={"unknown": marshmallow.EXCLUDE})()
     print(schema.load({"x": 1, "y": 2}))
 
 .. testoutput::

src/desert/_make.py

@@ -192,7 +192,7 @@ def field_for_schema(
     ...   red = 1
     >>> field_for_schema(Color).__class__
     <class 'marshmallow_enum.EnumField'>
-    >>> field_for_schema(Any).__class__
+    >>> field_for_schema(t.Any).__class__
     <class 'marshmallow.fields.Raw'>
     """