docs: add tutorial cross-links to README and reference docs

Author: nickprotop

README.md

@@ -261,6 +261,7 @@ dotnet run --project Examples/DemoApp
 
 | Guide | Description |
 |-------|-------------|
+| **[Tutorials](docs/tutorials/01-hello-window.md)** | Step-by-step guides: Hello Window → Dashboard → Settings App |
 | **[Examples Gallery](docs/EXAMPLES.md)** | All examples with screenshots |
 | **[Fluent Builders](docs/BUILDERS.md)** | WindowBuilder and control builder APIs |
 | **[Controls Reference](docs/CONTROLS.md)** | Complete guide to all 30+ UI controls |

docs/BUILDERS.md

@@ -1,5 +1,7 @@
 # Fluent Builders Reference
 
+> **New to SharpConsoleUI?** Start with the [Tutorials](tutorials/01-hello-window.md) — they cover `WindowBuilder` in context from the very first step.
+
 SharpConsoleUI provides fluent builder APIs for creating windows and controls with clean, chainable syntax.
 
 ## Table of Contents

docs/CONTROLS.md

@@ -2,6 +2,8 @@
 
 SharpConsoleUI provides 30+ built-in UI controls for building rich console applications.
 
+> **New to SharpConsoleUI?** Start with the [Tutorials](tutorials/01-hello-window.md) — step-by-step guides that build real apps from scratch.
+
 ## Table of Contents
 
 - [Overview](#overview)

docs/GRADIENTS.md

@@ -1,5 +1,7 @@
 # Gradients
 
+> **New to SharpConsoleUI?** Gradients are covered hands-on in [Tutorial 3: Settings App](tutorials/03-settings-app.md).
+
 SharpConsoleUI supports gradient colors for both text and window backgrounds, extending the existing `ColorGradient` system.
 
 ## Table of Contents

docs/MARKUP_SYNTAX.md

@@ -1,5 +1,7 @@
 # Markup Syntax Reference
 
+> **New to SharpConsoleUI?** Start with the [Tutorials](tutorials/01-hello-window.md) — markup is introduced in Tutorial 1.
+
 SharpConsoleUI includes a native markup parser that uses Spectre-compatible `[tag]text[/]` syntax. All markup is parsed directly into typed `Cell` structs -- no ANSI intermediate format, no external dependencies required.
 
 ## Basic Syntax