[WIP] Refactor everything server to be more modular and use recommended APIs.

* Updated architecture.md

* Refactor / renamed all addXPrompt, addXTool, and addXResource functions to registerX...

* Added the add tool

src/everything/tools/index.ts

@@ -1,10 +1,12 @@
 import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
-import { addToolEcho } from "./echo.js";
+import { registerEchoTool } from "./echo.js";
+import { registerAddTool } from "./add.js";
 
 /**
  * Register the tools with the MCP server.
  * @param server
  */
 export const registerTools = (server: McpServer) => {
-  addToolEcho(server);
+  registerEchoTool(server);
+  registerAddTool(server);
 };