Add a mention of tasks to the Primitives docs

Author: LucaButBoring

docs/docs/learn/architecture.mdx

@@ -132,6 +132,10 @@ MCP also defines primitives that _clients_ can expose. These primitives allow MC
 
 For more details about client primitives see [client concepts](./client-concepts).
 
+MCP also defines cross-cutting utility primitives that augment how requests are executed:
+
+- **Tasks**: Asynchronous execution wrappers that enable deferred result retrieval and status tracking for any MCP request (e.g., long-running computations, workflow automation, batch processing, multi-step operations)
+
 #### Notifications
 
 The protocol supports real-time notifications to enable dynamic updates between servers and clients. For example, when a server's available tools change—such as when new functionality becomes available or existing tools are modified—the server can send tool update notifications to inform connected clients about these changes. Notifications are sent as JSON-RPC 2.0 notification messages (without expecting a response) and enable MCP servers to provide real-time updates to connected clients.