langchain hub docs (#704)

Co-authored-by: scadEfUr <123224380+scadEfUr@users.noreply.github.com>

docs/index.rst

@@ -137,6 +137,8 @@ Additional Resources
 
 Additional collection of resources we think may be useful as you develop your application!
 
+- `LangChainHub <https://github.com/hwchase17/langchain-hub>`_: The LangChainHub is a place to share and explore other prompts, chains, and agents.
+
 - `Glossary <./glossary.html>`_: A glossary of all related terms, papers, methods, etc. Whether implemented in LangChain or not!
 
 - `Gallery <./gallery.html>`_: A collection of our favorite projects that use LangChain. Useful for finding inspiration or seeing how things were done in other applications.
@@ -152,6 +154,7 @@ Additional collection of resources we think may be useful as you develop your ap
    :name: resources
    :hidden:
 
+   LangChainHub <https://github.com/hwchase17/langchain-hub>
    ./glossary.md
    ./gallery.rst
    ./deployments.md

docs/modules/prompts/getting_started.md

@@ -80,6 +80,20 @@ Currently, the template should be formatted as a Python f-string. We also suppor
 :::
 
 
+## Load a prompt template from LangChainHub
+
+LangChainHub contains a collection of prompts which can be loaded directly via LangChain.
+
+
+```python
+from langchain.prompts import load_prompt
+
+prompt = load_prompt("lc://prompts/conversation/prompt.json")
+prompt.format(history="", input="What is 1 + 1?")
+```
+
+You can read more about LangChainHub and the prompts available with it [here](https://github.com/hwchase17/langchain-hub).
+
 ## Pass few shot examples to a prompt template
 
 Few shot examples are a set of examples that can be used to help the language model generate a better response.

langchain/prompts/loading.py

@@ -1,6 +1,7 @@
 """Load prompts from disk."""
 import importlib
 import json
+import os
 import tempfile
 from pathlib import Path
 from typing import Union
@@ -98,7 +99,7 @@ def _load_prompt(config: dict) -> PromptTemplate:
 def load_prompt(path: Union[str, Path]) -> BasePromptTemplate:
     """Unified method for loading a prompt from LangChainHub or local fs."""
     if isinstance(path, str) and path.startswith("lc://prompts"):
-        path = path.lstrip("lc://prompts/")
+        path = os.path.relpath("lc://prompts/conversation/prompt.json", "lc://prompts/")
         return _load_from_hub(path)
     else:
         return _load_prompt_from_file(path)