Improved readme

readme.md

@@ -26,12 +26,53 @@ The library is available as a nuget package. You can install it as any other nug
 </a>
 
 
-## Write less, achieve more
+## Documentation
+
+1. [Release notes and roadmap](https://www.questpdf.com/documentation/releases.html) - everything that is planned for future library iterations, description of new features and information about potential breaking changes.
+2. [Getting started tutorial](https://www.questpdf.com/documentation/getting-started.html) - a short and easy to follow tutorial showing how to design an invoice document under 200 lines of code.
+3. [API Reference](https://www.questpdf.com/documentation/api-reference.html) - a detailed description of behavior of all available components and how to use them with C# Fluent API.
+4. [Patterns and practices](https://www.questpdf.com/documentation/patterns-and-practices.html#document-metadata) - everything that may help you designing great reports and reusable code that is easy to maintain.
+
+## Example invoice
 
 Do you believe that creating a complete invoice document can take less than 200 lines of code? We have prepared for you a step-by-step instruction that shows every detail of this implementation and describes the best patterns and practices.
 
 For tutorial, documentation and API reference, please visit [the QuestPDF documentation](https://www.questpdf.com/documentation/getting-started.html).
 
-This repository contains sample implementation of the full, page-aware invoice similar to the one below. Let's get started!
+<a href="https://github.com/QuestPDF/example-invoice">
+  <img src="https://github.com/QuestPDF/example-invoice/raw/main/images/invoice.png" width="595px">
+</a>
 
-<img src="https://github.com/QuestPDF/example-invoice/raw/main/images/invoice.png" width="595px">
+Here you can find an example code showing how easy is to write and understand the fluent API:
+
+```csharp
+public void Compose(IContainer container)
+{
+    container
+        .PaddingHorizontal(50)
+        .PaddingVertical(50)
+        .Page(page =>
+        {
+            page.Header(ComposeHeader);
+            page.Content(ComposeContent);
+            page.Footer().AlignCenter().PageNumber("Page {number}");
+        });
+}
+
+void ComposeHeader(IContainer container)
+{
+    container.Row(row =>
+    {
+        row.RelativeColumn().Stack(column =>
+        {
+            column.Element().Text($"Invoice #{Model.InvoiceNumber}", TextStyle.Default.Size(20).Bold());
+            column.Element().Text($"Issue date: {Model.IssueDate:d}");
+            column.Element().Text($"Due date: {Model.DueDate:d}");
+        });
+        
+        row.ConstantColumn(100).Height(50).Placeholder();
+    });
+}
+
+// code describing content
+```