Simplify Tracks.__add__ method, support Chapter(s) & Track objects

devine/core/tracks/tracks.py

@@ -51,11 +51,12 @@ def __iter__(self) -> Iterator[AnyTrack]:
     def __len__(self) -> int:
         return len(self.videos) + len(self.audio) + len(self.subtitles)
 
-    def __add__(self, other: Tracks) -> Tracks:
-        if not isinstance(other, Tracks):
-            raise TypeError(f"Cannot only add {Tracks} objects with one another, not {type(other)}")
-
-        return Tracks(list(self) + list(other))
+    def __add__(
+        self,
+        other: Union[Tracks, Sequence[Union[AnyTrack, Chapter, Chapters]], Track, Chapter, Chapters]
+    ) -> Tracks:
+        self.add(other)
+        return self
 
     def __repr__(self) -> str:
         return "{name}({items})".format(