Docs: Update "split tasks" recipe to use gulp-hub

docs/recipes/split-tasks-across-multiple-files.md

@@ -1,22 +1,8 @@
 # Split tasks across multiple files
 
-If your `gulpfile.js` is starting to grow too large, you can split
-the tasks into separate files using one of the methods below.
-
-> Be advised, that this approach is [considered deprecated][deprecated]
-> and could lead to problems when migrating to the `gulp 4`.
-
-
-## Using `gulp-require-tasks`
-
-You can use the [gulp-require-tasks][gulp-require-tasks]
-module to automatically load all your tasks from the individual files.
-
-Please see the [module's README][gulp-require-tasks] for up-to-date instructions.
-
-## Using `require-dir`
-
-You can also use the [require-dir][require-dir] module to load your tasks manually.
+If your `gulpfile.js` is starting to grow too large, you can split the tasks
+into separate files by using the [gulp-hub](https://github.com/frankwallis/gulp-hub/tree/4.0)
+module as a [custom registry](https://github.com/phated/undertaker#registryregistryinstance).
 
 Imagine the following file structure:
 
@@ -28,20 +14,25 @@ tasks/
 └── test.js
 ```
 
-Install the `require-dir` module:
+Install the `gulp-hub` module:
 
 ```sh
-npm install --save-dev require-dir
+npm install --save-dev gulp-hub
 ```
 
 Add the following lines to your `gulpfile.js` file:
 
 ```js
-var requireDir = require('require-dir');
-var tasks = requireDir('./tasks');
-```
+'use strict';
+
+var gulp = require('gulp');
+var HubRegistry = require('gulp-hub');
 
+/* load some files into the registry */
+var hub = new HubRegistry(['tasks/*.js']);
+
+/* tell gulp to use the tasks just loaded */
+gulp.registry(hub);
+```
 
- [gulp-require-tasks]: https://github.com/betsol/gulp-require-tasks
- [require-dir]: https://github.com/aseemk/requireDir
- [deprecated]: https://github.com/gulpjs/gulp/pull/1554#issuecomment-202614391
+This recipe can also be found at https://github.com/frankwallis/gulp-hub/tree/4.0/examples/recipe