Require keyword args in models (#163)

* require kwargs for all models

* make tests use kwargs

* use the keyword args in the docs

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

conjugate/_typing.py

@@ -2,26 +2,18 @@
 
 
 class NUMERIC(Protocol):
-    def __add__(self, other: "NUMERIC") -> "NUMERIC":
-        ...  # pragma: no cover
+    def __add__(self, other: "NUMERIC") -> "NUMERIC": ...  # pragma: no cover
 
-    def __radd__(self, other: "NUMERIC") -> "NUMERIC":
-        ...  # pragma: no cover
+    def __radd__(self, other: "NUMERIC") -> "NUMERIC": ...  # pragma: no cover
 
-    def __sub__(self, other: "NUMERIC") -> "NUMERIC":
-        ...  # pragma: no cover
+    def __sub__(self, other: "NUMERIC") -> "NUMERIC": ...  # pragma: no cover
 
-    def __rsub__(self, other: "NUMERIC") -> "NUMERIC":
-        ...  # pragma: no cover
+    def __rsub__(self, other: "NUMERIC") -> "NUMERIC": ...  # pragma: no cover
 
-    def __mul__(self, other: "NUMERIC") -> "NUMERIC":
-        ...  # pragma: no cover
+    def __mul__(self, other: "NUMERIC") -> "NUMERIC": ...  # pragma: no cover
 
-    def __rmul__(self, other: "NUMERIC") -> "NUMERIC":
-        ...  # pragma: no cover
+    def __rmul__(self, other: "NUMERIC") -> "NUMERIC": ...  # pragma: no cover
 
-    def __truediv__(self, other: "NUMERIC") -> "NUMERIC":
-        ...  # pragma: no cover
+    def __truediv__(self, other: "NUMERIC") -> "NUMERIC": ...  # pragma: no cover
 
-    def __rtruediv__(self, other: "NUMERIC") -> "NUMERIC":
-        ...  # pragma: no cover
+    def __rtruediv__(self, other: "NUMERIC") -> "NUMERIC": ...  # pragma: no cover