add extra to Model.Meta, update docs and bump version

tests/test_model_definition/test_extra_ignore_parameter.py

@@ -0,0 +1,28 @@
+import databases
+import sqlalchemy
+
+import ormar
+from ormar import Extra
+from tests.settings import DATABASE_URL
+
+database = databases.Database(DATABASE_URL, force_rollback=True)
+metadata = sqlalchemy.MetaData()
+
+
+class Child(ormar.Model):
+    class Meta(ormar.ModelMeta):
+        tablename = "children"
+        metadata = metadata
+        database = database
+        extra = Extra.ignore
+
+    id: int = ormar.Integer(name="child_id", primary_key=True)
+    first_name: str = ormar.String(name="fname", max_length=100)
+    last_name: str = ormar.String(name="lname", max_length=100)
+
+
+def test_allow_extra_parameter():
+    child = Child(first_name="Test", last_name="Name", extra_param="Unexpected")
+    assert child.first_name == "Test"
+    assert child.last_name == "Name"
+    assert not hasattr(child, "extra_param")