docs: Add changelog.md - #57

D:\a\AngleSharp.Diffing\AngleSharp.Diffing\src\AngleSharp.Diffing.Tests\ShouldlyTestExtensions.cs(3,21): warning CA1515: Because an application's API isn't typically referenced from outside the assembly, types can be made internal (https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca1515) [D:\a\AngleSharp.Diffing\AngleSharp.Diffing\src\AngleSharp.Diffing.Tests\AngleSharp.DiffingTests.csproj]

D:\a\AngleSharp.Diffing\AngleSharp.Diffing\src\AngleSharp.Diffing.Tests\DiffingTestFixture.cs(5,14): warning CA1515: Because an application's API isn't typically referenced from outside the assembly, types can be made internal (https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca1515) [D:\a\AngleSharp.Diffing\AngleSharp.Diffing\src\AngleSharp.Diffing.Tests\AngleSharp.DiffingTests.csproj]

D:\a\AngleSharp.Diffing\AngleSharp.Diffing\src\AngleSharp.Diffing.Tests\DiffingTestBase.cs(3,23): warning CA1515: Because an application's API isn't typically referenced from outside the assembly, types can be made internal (https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca1515) [D:\a\AngleSharp.Diffing\AngleSharp.Diffing\src\AngleSharp.Diffing.Tests\AngleSharp.DiffingTests.csproj]

D:\a\AngleSharp.Diffing\AngleSharp.Diffing\src\AngleSharp.Diffing.Tests\Core\HtmlDifferenceEngineTest.cs(520,26): warning CA1515: Because an application's API isn't typically referenced from outside the assembly, types can be made internal (https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca1515) [D:\a\AngleSharp.Diffing\AngleSharp.Diffing\src\AngleSharp.Diffing.Tests\AngleSharp.DiffingTests.csproj]

D:\a\AngleSharp.Diffing\AngleSharp.Diffing\src\AngleSharp.Diffing.Tests\Core\HtmlDifferenceEngineTest.cs(513,26): warning CA1515: Because an application's API isn't typically referenced from outside the assembly, types can be made internal (https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca1515) [D:\a\AngleSharp.Diffing\AngleSharp.Diffing\src\AngleSharp.Diffing.Tests\AngleSharp.DiffingTests.csproj]

D:\a\AngleSharp.Diffing\AngleSharp.Diffing\src\AngleSharp.Diffing.Tests\Strategies\TextNodeStrategies\TextNodeTestBase.cs(5,23): warning CA1515: Because an application's API isn't typically referenced from outside the assembly, types can be made internal (https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca1515) [D:\a\AngleSharp.Diffing\AngleSharp.Diffing\src\AngleSharp.Diffing.Tests\AngleSharp.DiffingTests.csproj]

D:\a\AngleSharp.Diffing\AngleSharp.Diffing\src\AngleSharp.Diffing.Tests\Core\DiffingEngineTestBase.cs(3,23): warning CA1515: Because an application's API isn't typically referenced from outside the assembly, types can be made internal (https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca1515) [D:\a\AngleSharp.Diffing\AngleSharp.Diffing\src\AngleSharp.Diffing.Tests\AngleSharp.DiffingTests.csproj]

D:\a\AngleSharp.Diffing\AngleSharp.Diffing\src\AngleSharp.Diffing.Tests\ShouldlyTestExtensions.cs(3,21): warning CA1515: Because an application's API isn't typically referenced from outside the assembly, types can be made internal (https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca1515) [D:\a\AngleSharp.Diffing\AngleSharp.Diffing\src\AngleSharp.Diffing.Tests\AngleSharp.DiffingTests.csproj]

D:\a\AngleSharp.Diffing\AngleSharp.Diffing\src\AngleSharp.Diffing.Tests\DiffingTestFixture.cs(5,14): warning CA1515: Because an application's API isn't typically referenced from outside the assembly, types can be made internal (https://learn.microsoft.com/dotnet/fundamentals/code-analysis/quality-rules/ca1515) [D:\a\AngleSharp.Diffing\AngleSharp.Diffing\src\AngleSharp.Diffing.Tests\AngleSharp.DiffingTests.csproj]