Update docs for whylabs (langkit) callback handler (#7293)

- Description: Update docs for whylabs callback handler
  - Issue: none
  - Dependencies: none
  - Tag maintainer: @agola11 
  - Twitter handle: @useautomation @whylabs

---------

Co-authored-by: Bagatur <baskaryan@gmail.com>
Co-authored-by: Jamie Broomall <jamie@whylabs.ai>

langchain/callbacks/whylabs_callback.py

@@ -48,7 +48,48 @@ def import_langkit(
 
 
 class WhyLabsCallbackHandler(BaseCallbackHandler):
-    """WhyLabs CallbackHandler."""
+    """
+    Callback Handler for logging to WhyLabs. This callback handler utilizes
+    `langkit` to extract features from the prompts & responses when interacting with
+    an LLM. These features can be used to guardrail, evaluate, and observe interactions
+    over time to detect issues relating to hallucinations, prompt engineering,
+    or output validation. LangKit is an LLM monitoring toolkit developed by WhyLabs.
+
+    Here are some examples of what can be monitored with LangKit:
+    * Text Quality
+      - readability score
+      - complexity and grade scores
+    * Text Relevance
+      - Similarity scores between prompt/responses
+      - Similarity scores against user-defined themes
+      - Topic classification
+    * Security and Privacy
+      - patterns - count of strings matching a user-defined regex pattern group
+      - jailbreaks - similarity scores with respect to known jailbreak attempts
+      - prompt injection - similarity scores with respect to known prompt attacks
+      - refusals - similarity scores with respect to known LLM refusal responses
+    * Sentiment and Toxicity
+      - sentiment analysis
+      - toxicity analysis
+
+    For more information, see https://docs.whylabs.ai/docs/language-model-monitoring
+    or check out the LangKit repo here: https://github.com/whylabs/langkit
+
+    ---
+    Args:
+        api_key (Optional[str]): WhyLabs API key. Optional because the preferred
+            way to specify the API key is with environment variable
+            WHYLABS_API_KEY.
+        org_id (Optional[str]): WhyLabs organization id to write profiles to.
+            Optional because the preferred way to specify the organization id is
+            with environment variable WHYLABS_DEFAULT_ORG_ID.
+        dataset_id (Optional[str]): WhyLabs dataset id to write profiles to.
+            Optional because the preferred way to specify the dataset id is
+            with environment variable WHYLABS_DEFAULT_DATASET_ID.
+        sentiment (bool): Whether to enable sentiment analysis. Defaults to False.
+        toxicity (bool): Whether to enable toxicity analysis. Defaults to False.
+        themes (bool): Whether to enable theme analysis. Defaults to False.
+    """
 
     def __init__(self, logger: Logger):
         """Initiate the rolling logger"""