Add alt_str method and enhance docstrings for properties

Introduced the `alt_str` method to provide a concise string representation of accounts. Additionally, improved and detailed the docstrings for `coa_slug` and `entity_slug` properties, ensuring clarity and consistency in code documentation.

Author: elarroba

django_ledger/models/accounts.py

@@ -472,15 +472,55 @@ def __str__(self):
             x5=self.code
         )
 
+    def alt_str(self):
+        """
+        Returns a formatted string representation of the object.
+
+        The formatted string includes the code, name, role, and balance type
+        of the object. The role is converted to uppercase for consistency,
+        and the balance type is displayed as is. This method provides a
+        concise textual representation for quick identification or display.
+
+        Returns:
+            str: A formatted string in the format 'code: name (ROLE/BALANCE_TYPE)'.
+        """
+        return f'{self.code}: {self.name} ({self.role.upper()}/{self.balance_type})'
+
     @property
     def coa_slug(self):
+        """
+        Property that retrieves the `coa_slug` attribute from the object. If the attribute
+        is not found, it fetches the `slug` attribute from the `coa_model`.
+
+        Attributes:
+            _coa_slug (str): Cached value of the `coa_slug` if it exists.
+            coa_model (Any): Object containing the `slug` attribute that serves
+                as a fallback when `_coa_slug` is not present.
+
+        Returns:
+            str: The value of `_coa_slug` if defined, or the `slug` attribute from
+            `coa_model` if `_coa_slug` is not available.
+        """
         try:
             return getattr(self, '_coa_slug')
         except AttributeError:
             return self.coa_model.slug
 
     @property
     def entity_slug(self):
+        """
+            Retrieve the slug value associated with the entity.
+
+            This property method returns the value of the private attribute
+            '_entity_slug' for the current instance. The purpose of the
+            slug is typically to provide a URL-friendly string representing
+            the entity.
+
+            Returns
+            -------
+            Any
+                The value of the '_entity_slug' attribute.
+        """
         return getattr(self, '_entity_slug')
 
     @classmethod