Add XML docs

YesNt.Interpreter/Runtime/StatementRuntimeInfo.cs

@@ -1,6 +1,16 @@
 namespace YesNt.Interpreter.Runtime;
 
+/// <summary>
+/// Base class for all classes that host statement handler methods.
+/// Subclasses declare methods decorated with <see cref="Attributes.StatementAttribute"/> or
+/// <see cref="Attributes.StaticStatementAttribute"/>; the source generator
+/// (<c>GeneratedStatementRegistry</c>) discovers these at compile time and wires them up.
+/// </summary>
 internal abstract class StatementRuntimeInformation
 {
+    /// <summary>
+    /// Gets or sets the runtime state for the current execution context.
+    /// Injected by the generated registry before any handler is invoked.
+    /// </summary>
     public RuntimeInformation RuntimeInfo { get; set; }
 }