fix typo moudles -> modules (#178)

runtime/manual/index.mdx

@@ -363,7 +363,7 @@ Deno provides a compatibility layer that enables your code to use
 [Node.js built-in modules and third-party modules from npm](./node/index.md).
 Using Node and npm modules in your code looks a lot like using standard Deno
 modules, except you'll use either a `node:` or `npm:` specifier when importing
-Node built-ins or npm moudles, respectively.
+Node built-ins or npm modules, respectively.
 
 To see how it works, create a file called `server.js` and include the
 following - a simple HTTP server using the popular