title: Yii2 php init command
body: <p>What does <code>php init</code> command actually do?</p>
  
  <p>When I run this command in cmd after creating my project using this command: <code>composer create-project --prefer-dist yiisoft/yii2-app-advanced advanced</code></p>
  
  <p>I see many files generated in different locations like common, backend, frontend.</p>
  
  <pre><code> `some@user:/var/www/html/yiiapp$ php init
    Yii Application Initialization Tool v1.0
  
    Which environment do you want the application to be initialized in?
  
  [0] Development
   [1] Production
  
  Your choice [0-1, or "q" to quit] 0
  
  Initialize the application under 'Development' environment? [yes|no] yes
  
  Start initialization ...
  
    exist common/config/main-local.php
          ...overwrite? [Yes|No|All|Quit] All
  overwrite common/config/main-local.php
  unchanged common/config/params-local.php
  unchanged yii
  overwrite backend/config/main-local.php
  unchanged backend/config/params-local.php
  unchanged backend/web/index-test.php
  unchanged backend/web/index.php
  unchanged api/web/index-test.php
  unchanged api/web/index.php
  overwrite frontend/config/main-local.php
  unchanged frontend/config/params-local.php
  unchanged frontend/web/index-test.php
  unchanged frontend/web/index.php
  unchanged console/config/main-local.php
  unchanged console/config/params-local.php
   generate cookie validation key in backend/config/main-local.php
   generate cookie validation key in frontend/config/main-local.php
    chmod 0777 backend/runtime
    chmod 0777 backend/web/assets
    chmod 0777 frontend/runtime
    chmod 0777 frontend/web/assets
    chmod 0755 yii
    chmod 0755 tests/codeception/bin/yii
  
  ... initialization completed.`
  </code></pre>