add readme & docstrings

parsers.py

@@ -13,10 +13,31 @@ from model import Transaction
 class TransactionParser(ABC):
     @abstractmethod
     def match(self, msg: Message) -> bool:
+        """
+        Determines if the given email message matches the criteria for this parser.
+
+        Args:
+            msg (Message): The email message to evaluate.
+
+        Returns:
+            bool: True if the message matches the parser's criteria, False otherwise.
+        """
         pass
 
     @abstractmethod
     def extract(self, msg: EmailMessage) -> Transaction:
+        """
+        Extracts transaction details from the given email message.
+
+        Args:
+            msg (EmailMessage): The email message to parse.
+
+        Returns:
+            Transaction: A Transaction object containing the extracted details.
+
+        Raises:
+            TransactionParsingFailed: If the message cannot be parsed successfully.
+        """
         pass