Add sample code link and SQL query parsing details

- Added a link to the complete sample code at Sample.csproj.
- Included explanation on parsing SQL queries into AST, converting back to SQL with ToSql, and inspecting structure using ToTreeString.

Author: mk3008

README.md

@@ -40,6 +40,8 @@ NuGet\Install-Package Carbunqlex
 
 ## 📖 Documentation
 
+The complete code for the sample used here can be found at [Sample.csproj](https://github.com/mk3008/CarbunqleX/tree/91c752ba382df24238451bad0416bfd4f80bbf82/demo/Sample)
+
 ### **1. Parsing a SQL Query**
 
 Let's start by parsing a simple SQL query into an AST using `QueryAstParser.Parse`. We will then convert it back to SQL with `ToSql` and inspect its structure using `ToTreeString`.