chore(readme): how to install sqlite with extensions support

Author: Daniele Briggi

README.md

@@ -7,7 +7,8 @@
 ![PyPI - Version](https://img.shields.io/pypi/v/sqlite-rag?link=https%3A%2F%2Fpypi.org%2Fproject%2Fsqlite-rag%2F)
 ![PyPI - Python Version](https://img.shields.io/pypi/pyversions/sqlite-rag?link=https%3A%2F%2Fpypi.org%2Fproject%2Fsqlite-rag)
 
-A hybrid search engine built on SQLite with [SQLite AI](https://github.com/sqliteai/sqlite-ai) and [SQLite Vector](https://github.com/sqliteai/sqlite-vector) extensions. SQLite RAG combines vector similarity search with full-text search ([FTS5](https://www.sqlite.org/fts5.html) extension) using Reciprocal Rank Fusion (RRF) for enhanced document retrieval.
+A hybrid search engine built on SQLite with [SQLite AI](https://github.com/sqliteai/sqlite-ai) and [SQLite Vector](https://github.com/sqliteai/sqlite-vector) extensions.
+SQLite RAG combines vector similarity search with full-text search ([FTS5](https://www.sqlite.org/fts5.html) extension) using Reciprocal Rank Fusion (RRF) for enhanced document retrieval.
 
 ## Features
 
@@ -20,6 +21,13 @@ A hybrid search engine built on SQLite with [SQLite AI](https://github.com/sqlit
 
 ## Installation
 
+### Prerequisites
+
+SQLite RAG requires SQLite with _extension loading_ support.
+If you encounter extension loading issues (e.g., `'sqlite3.Connection' object has no attribute 'enable_load_extension'`), follow the setup guides for [macOS](https://github.com/sqliteai/sqlite-extensions-guide/blob/main/platforms/macos.md#python-on-macos) or [Windows](https://github.com/sqliteai/sqlite-extensions-guide/blob/main/platforms/windows.md#using-sqlite-with-python).
+
+### Install SQLite RAG
+
 ```bash
 python3 -m venv .venv
 source .venv/bin/activate  # On Windows: .venv\Scripts\activate