chore(cli): fix some DOC rules (preview) (#32839)

Co-authored-by: Mason Daugherty <mason@langchain.dev>

libs/cli/langchain_cli/utils/find_replace.py

@@ -4,7 +4,15 @@ from pathlib import Path
 
 
 def find_and_replace(source: str, replacements: dict[str, str]) -> str:
-    """Find and replace text in a string."""
+    """Find and replace text in a string.
+
+    Args:
+        source: The source string.
+        replacements: A dictionary of `{find: replace}` pairs.
+
+    Returns:
+        The modified string.
+    """
     rtn = source
 
     # replace keys in deterministic alphabetical order