What functionality does the Sitecore.LayoutService NuGet package provide to developers?

The Sitecore.LayoutService NuGet package primarily provides developers with access to assemblies and types that are essential for extending the output of the layout service. This service enables the rendering of Sitecore content in a headless manner, allowing developers to build applications that consume Sitecore content through APIs. By utilizing this package, developers can integrate and customize how content is rendered and interact with the Sitecore presentation layer programmatically.

The layout service is crucial for scenarios where developers need to fetch layout definitions and render items in a decoupled way, such as in Single Page Applications (SPAs) or other modern front-end frameworks. Therefore, the ability to access these assemblies and types ensures that developers can effectively extend and customize their content delivery processes in line with their application architecture.