Initial upload: git-insights-cli with CI/CD workflow

src/formatters/base.py

@@ -0,0 +1,11 @@
+from abc import ABC, abstractmethod
+from typing import Any
+
+
+class BaseFormatter(ABC):
+    """Base class for formatters."""
+
+    @abstractmethod
+    def format(self, data: Any) -> str:
+        """Format data to string."""
+        pass