added fc-unst-mongodb notebook (#570)

Co-authored-by: ajaykrish2303 <ag8172@nyu.edu>

Author: ajay23-uns

examplecode/notebooks.mdx

@@ -6,6 +6,13 @@ description: "Notebooks contain complete working sample code for end-to-end solu
 ---
 
 <CardGroup cols={2}>
+   <Card title="RAG for Online Documentations" href="https://colab.research.google.com/drive/1F1LkM_HwuwruQb5rwsK5Fj_up15hHeLi">
+    <br/>
+       Crawl websites with Firecrawl and build a RAG workflow powered by Unstructured and MongoDB Atlas vector search.
+    <br/>
+       ``Unstructured API`` ``Workflows`` ``MongoDB``
+    <br/>
+    </Card>
     <Card title="Unstructured Workflow Endpoint Quickstart" href="https://colab.research.google.com/drive/13f5C9WtUvIPjwJzxyOR3pNJ9K9vnF4ww">
     <br/>
        Build an end-to-end workflow in Unstructured programmatically by using the Unstructured Workflow Endpoint.