Clarify WordPress query handling with SQLite integration (#305)

### What this PR does
Adds a technical FAQ entry explaining how the SQLite integration
interacts with WordPress database queries.

### Why this is needed
Users testing SQLite may assume core query behavior changes.
This clarification explains that the wpdb API remains unchanged
while queries are adapted internally.

### What I tested
Reviewed the documentation for technical accuracy and consistency
with the existing plugin behavior.

Author: Nitinrev787

readme.txt

@@ -36,3 +36,12 @@ Feedback is encouraged and much appreciated, especially since this plugin is a f
 = How can I contribute to the plugin? =
 
 Contributions are always welcome! Learn more about how to get involved in the [Core Performance Team Handbook](https://make.wordpress.org/performance/handbook/get-involved/).
+
+= Does this plugin change how WordPress queries are executed? =
+
+The plugin replaces the default MySQL-based database layer with an
+SQLite-backed implementation. Core WordPress code continues to use
+the wpdb API, while queries are internally adapted to be compatible
+with SQLite syntax and behavior.
+
+