Document main logic function for processing filepaths

Fix docstring on confirm function

vault2vault.py

@@ -73,6 +73,19 @@ def _process_file(  # pylint: disable=too-many-statements
     backup: bool,
     ignore: bool,
 ) -> None:
+    """Determine whether a filepath includes vaulted data and if so, rekey it
+
+    :param path: Path to the file to check
+    :param old: VaultLib object with the current (old) vault password encoded in it
+    :param new: VaultLib object with the target (new) vault password encoded in it
+    :param interactive: Whether to prompt interactively for confirmation before each
+                        rekey operation
+    :param backup: Whether to copy the original file to a backup before making any
+                   in-place changes
+    :param ignore: Whether to ignore any errors that come from failing to decrypt
+                   any vaulted data
+    """
+
     logger = logging.getLogger(__name__)
 
     logger.debug(f"Processing file {path}")
@@ -348,6 +361,7 @@ def _load_password(
                   the password will be prompted for interactively.
     :param desc: Description text to inject into the interactive password prompt. Useful when using
                  this function multiple times to identify different passwords to the user.
+    :param confirm: Whether to prompt twice for the input and check that the two inputs match
     :returns: Populated vault secret object with the loaded password
     """