Add a search engine linking with Stave using Streamlit

Add an example with the following features:

1. a search engine using streamlit.
2. link the search results to relevant stave documents.

Start by locating the repository's existing examples and the entry points for Streamlit and Stave documents. Trace how documents can be searched and how a result could identify its source document. Done means a runnable Streamlit example performs search and links each result to the relevant Stave document.

Written by the indexing model from the issue text.