feat: llamaindex and langchain (#165)

* feat: llamaindex and langchain

* fix: lint

* fix: size

* fix: instructions

* fix: ci

* fix: connection string

* fix: project connection string

* nb: clean

* readmes

Author: santiagxf

scenarios/langchain/README.md

@@ -0,0 +1,30 @@
+---
+page_type: sample
+languages:
+- python
+products:
+- ai-services
+- azure-openai
+description: Examples about how to use LangChain with Azure AI Foundry.
+---
+
+## Develop applications with LangChain and Azure AI Foundry
+
+### Overview
+
+In this article, you learn how to use LangChain with models deployed from the Azure AI model catalog in Azure AI Foundry portal.
+
+### Objective
+
+The main objective of this tutorial are:
+
+ - Learn how to use the package `langchain-core`, and `langchain-azure-ai` to build applications using models deployed to Azure AI Foundry.
+ - Learn how to configure the use of different models in your chains.
+ - Learn how to debug your code.
+ - Learn how to trace your applications using Azure AI Foundry.
+
+### Programming Languages
+
+ - Python
+
+### Estimated Runtime: 30 mins