renaming docs examples (#972)

* renaming docs examples

* tweaks

docs/examples/models_construct.py

@@ -0,0 +1,27 @@
+from pydantic import BaseModel
+
+class User(BaseModel):
+    id: int
+    age: int
+    name: str = 'John Doe'
+
+original_user = User(id=123, age=32)
+
+user_data = original_user.dict()
+print(user_data)
+fields_set = original_user.__fields_set__
+print(fields_set)
+
+# ...
+# pass user_data and fields_set to RPC or save to the database etc.
+# ...
+
+# you can then create a new instance of User without
+# re-running validation which would be unnecessary at this point:
+new_user = User.construct(_fields_set=fields_set, **user_data)
+print(repr(new_user))
+print(new_user.__fields_set__)
+
+# construct can be dangerous, only use it with validated data!:
+bad_user = User.construct(id='dog')
+print(repr(bad_user))