Fix API omissions

Author: mwcraig

src/astro_image_display_api/interface_definition.py

@@ -119,7 +119,7 @@ def save(self, filename: str | os.PathLike, overwrite: bool = False) -> None:
 
     # Marker-related methods
     @abstractmethod
-    def start_marking(self, marker_name: str | None = None) -> None:
+    def start_marking(self, marker_name: str | None = None, marker: Any = None) -> None:
         """
         Start interactive marking of points on the image.
 
@@ -128,6 +128,10 @@ def start_marking(self, marker_name: str | None = None) -> None:
         marker_name : str, optional
             The name of the marker set to use. If not given, a unique
             name will be generated.
+
+        marker : Any, optional
+            The marker to use. If not given, a default marker will be
+            used.
         """
         raise NotImplementedError
 
@@ -265,8 +269,7 @@ def offset_by(self, dx: float | Quantity, dy: float | Quantity) -> None:
         """
         raise NotImplementedError
 
-    @abstractmethod
-    def zoom(self) -> None:
+    def zoom(self, val) -> None:
         """
         Zoom in or out by the given factor.