XUnit Setup Project docs added

Author: vivekkpatel

docs/UnitTest/1 Basics.md

@@ -0,0 +1,60 @@
+# XUnit Basics
+
+## Overview
+- XUnit is a popular open-source unit testing framework for .NET applications.
+- Good support for modern .NET features and is widely adopted in the .NET community.
+- [XUnit](https://xunit.net/)
+
+## Setting up XUnit in your project
+- Create .Net 8 Class Library project with `MathUtil` class.
+- XUnit test project from Visual Studio template.
+- Remove Old XUnit package
+- Add ` xunit.v3` Nuget package to test project.
+- Update `xunit.runner.visualstudio` to latest version.
+- Update `Microsoft.NET.Test.Sdk` to latest version.
+- Add `MathUtilTest` class to test project.
+
+```csharp title="MathUtil Class"
+public  static class MathUtil
+{
+    public static int Add(int a, int b)
+    {
+        return a + b;
+    }
+    public static int Subtract(int a, int b)
+    {
+        return a - b;
+    }
+    public static int Multiply(int a, int b)
+    {
+        return a * b;
+    }
+    public static double Divide(int a, int b)
+    {
+        if (b == 0)
+        {
+            throw new DivideByZeroException("Denominator cannot be zero.");
+        }
+        return (double)a / b;
+    }
+}
+```
+
+```csharp title="MathUtilTests Class"
+public class MathUtilTest
+{
+    [Fact]
+    public void TestAdd()
+    {
+        //Arrange
+        var a = 1;
+        var b = 2;
+
+        //Act
+        var result = MathUtil.Add(a, b);
+
+        //Assert
+        Assert.Equal(3, result);
+    }
+}
+```

mkdocs.yml

@@ -55,6 +55,7 @@ markdown_extensions:
         - name: mermaid
           class: mermaid
           format: !!python/name:pymdownx.superfences.fence_code_format
+  - attr_list # for code block titles and other attributes
   - pymdownx.arithmatex: # for rendering math equations
       generic: true
   - def_list # List extensions