feat: create chat message

src/AnthropicClient/Models/Content.cs

@@ -0,0 +1,29 @@
+using System.Text.Json.Serialization;
+
+namespace AnthropicClient.Models;
+
+/// <summary>
+/// Represents part of the content of a chat message.
+/// </summary>
+public abstract class Content
+{
+  /// <summary>
+  /// Gets the type of the content.
+  /// </summary>
+  public string Type { get; init; } = string.Empty;
+
+  [JsonConstructor]
+  internal Content()
+  {
+  }
+
+  /// <summary>
+  /// Initializes a new instance of the <see cref="Content"/> class.
+  /// </summary>
+  /// <param name="type">The type of the content.</param>
+  /// <returns>A new instance of the <see cref="Content"/> class.</returns>
+  protected Content(string type)
+  {
+    Type = type;
+  }
+}