Fixed typo in readme

Author: PolnerA

readme.md

@@ -40,7 +40,7 @@ _(More information on how to use Github Packages in Nuget Package Manager can be
 
 ## Usage
 
-You only need five lines of code, to generate and view your first QR code.
+You only need four lines of code, to generate and view your first QR code.
 
 ```csharp
 QRCodeGenerator qrGenerator = new QRCodeGenerator();