Fixes #4324: removed old way of developing Yii from the docs since app/link is…

docs/internals/getting-started.md

 Getting started with Yii2 development
 =====================================
 
-The best way to have a locally runnable webapp that uses codebase cloned from main repository is to use `yii2-dev`
-Composer package. Here's how to do it:
-
-1. `git clone https://github.com/yiisoft/yii2-app-basic`.
-2. Remove `.git` directory from cloned directory.
-3. Change `composer.json`. Instead of all stable requirements add just one `"yiisoft/yii2-dev": "*"`.
-4. Execute `composer create-project`. Do not add `--prefer-dist` to the command since it will not download git repository
-   then.
-5. Now you have working playground that uses latest code.
-
-Note that requirements of extensions that come with `yii2-dev` are not loaded automatically.
-If you want to use an extension, check if there are dependencies suggested for it and add them
-to your `composer.json`. You can see suggested packages by running `composer show yiisoft/yii2-dev`.
-
-If you're core developer there's no extra step needed. You can change framework code under
-`vendor/yiisoft/yii2-dev` and push it to main repository.
-
-If you're not core developer or want to use your own fork for pull requests:
-
-1. Fork `https://github.com/yiisoft/yii2` and get your own repository address such as
-   `git://github.com/username/yii2.git`.
-2. Edit `vendor/yiisoft/yii2-dev/.git/config`. Change remote `origin` url to your own:
-
-```
-[remote "origin"]
-  url = git://github.com/username/yii2.git
-```
-
-> Hint: The workflow of forking a package and pushing changes back into your fork and then sending a pull-request to the
-  maintainer is the same for all extensions you require via composer.
-
-Please refer to [Git workflow for Yii 2 contributors](git-workflow.md) for details about creating pull requests.
-
-
-An Alternative way
-------------------
-
 1. Clone your fork of yii2 `git clone git@github.com:<yourname>/yii2`.
 2. Change into the repo folder `cd yii2`.
 3. run `./build/build app/link basic` to install composer dependecies for the basic app.
@@ -53,6 +16,8 @@ You may also add the yii2 upstream repo to pull the latest changes:
 git remote add upstream https://github.com/yiisoft/yii2.git
 ```
 
+Please refer to [Git workflow for Yii 2 contributors](git-workflow.md) for details about creating pull requests.
+
 ### Unit tests
 
 To run the unit tests you have to install composer packages for the dev-repo.