refactor: standardize constructor signatures for notifiers

Updated constructors in BaseNotifier, Matrix, and NotifySend classes
to consistently use kwargs for initialization. Simplifies the
BaseNotifier class and reduces the need for extra positional
arguments in derived classes, leading to clearer and more flexible
instantiation.

src/trackbert/classes/notifier.py

@@ -1,5 +1,5 @@
 class BaseNotifier:
-    def __init__(self, *args, **kwargs):
+    def __init__(self, **kwargs):
         pass
 
     def notify(self, title: str, message: str, urgent: bool = False) -> None:

src/trackbert/notifiers/matrix.py

@@ -7,8 +7,8 @@ from ..classes.notifier import BaseNotifier
 
 
 class Matrix(BaseNotifier):
-    def __init__(self, config: Dict[str, Any], *args, **kwargs):
+    def __init__(self, **kwargs):
-        self.config = config
+        self.config = kwargs["config"]
 
     def enabled(self) -> bool:
         return bool(self.config)

src/trackbert/notifiers/notify_send.py

@@ -8,7 +8,7 @@ from pathlib import Path
 
 
 class NotifySend(BaseNotifier):
-    def __init__(self, *args, **kwargs):
+    def __init__(self, **kwargs):
         pass
 
     def notify(