Merge branch '1.3'

* 1.3:
  Fix changelog looks
  Review fixes + catalog structure change explanation
  Minimalistic UPGRADE path from Sylius 1.2 to 1.3

CHANGELOG-1.3.md

@@ -2,7 +2,7 @@
 
 ## v1.3.0-BETA (2018-09-24)
 
-## TL;DR
+#### TL;DR
 
 - Bumped minimal PHP version to 7.2 ([#9498](https://github.com/Sylius/Sylius/pull/9498))
 - Changed to Symfony 4 directory structure ([#9643](https://github.com/Sylius/Sylius/pull/9643))

UPGRADE-1.3.md

@@ -1 +1,31 @@
 # UPGRADE FROM `v1.2.X` TO `v1.3.0`
+
+## Configuration
+
+* **Sylius 1.3** requires **PHP 7.2**, then following configuration should be changed:
+    * `composer.json`:
+        * `"php": "^7.1"` -> `"php": "^7.2"`
+        * `"config.platform.php": "7.1.18"` -> `"config.platform.php": "7.2.4"`
+    * `.travis.yml` (if you're using Travis CI):
+        * leave only configuration for `PHP 7.2`
+
+* Copy [.env.dist from Sylius 1.3](https://github.com/Sylius/Sylius-Standard/blob/1.3/.env.dist) to your application root:
+    * Basing on this file create env files for your environments (`.env`, `.env.test` etc.)
+    * Add `.env` and `.env.test` files to `.gitignore` (or any other not-dist files you've created in a previous step)
+    * Configure environmental variables (especially `DATABASE_URL`)
+
+* If you want to reuse Sylius Behat contexts, it could be required to run
+`composer require friends-of-behat/page-object-extension —-dev` which is now used in Sylius test suite
+
+## Catalog structure change
+
+**Sylius 1.3** uses new directory structure, introduced in **Symfony 4**. Even though it's not required,
+we strongly encourage you to follow this convention. Take a look at
+[official Symfony upgrade documentation](symfony.com/doc/current/setup/flex.html#upgrading-existing-applications-to-flex),
+to know what exactly should be done.
+
+#### Remember!
+
+After upgrading the catalog structure, copy [public/index.php](https://github.com/Sylius/Sylius-Standard/blob/1.3/public/index.php)
+and [bin/console](https://github.com/Sylius/Sylius-Standard/blob/1.3/bin/console) files from **Sylius-Standard**
+to make the whole process completed.