Update 2. Demonstrate ability to process URLs in Magento.md

Author: simpleadm

2. Request Flow Processing/2. Demonstrate ability to process URLs in Magento.md

@@ -86,10 +86,12 @@ Module UrlRewrite:
 - \Magento\UrlRewrite\Model\UrlPersistInterface::replace
 
 Product:
+
 - event `catalog_product_save_before` - generate URL key by product name (if url key wasn't provided)
   * [ProductUrlKeyAutogeneratorObserver](https://github.com/magento/magento2/blob/2.2-develop/app/code/Magento/CatalogUrlRewrite/Observer/ProductUrlKeyAutogeneratorObserver.php)
   * [\Magento\CatalogUrlRewrite\Model\ProductUrlPathGenerator::getUrlKey](https://github.com/magento/magento2/blob/2.2-develop/app/code/Magento/CatalogUrlRewrite/Model/ProductUrlPathGenerator.php#L125)
-- event `catalog_product_save_after` - generate and replace URL rewrites (if changed url_key, categories, websites or visibility)
+  
+- event `catalog_product_save_after` - generate and replace URL rewrites (when changed url_key, categories, websites or visibility)
   * [ProductProcessUrlRewriteSavingObserver](https://github.com/magento/magento2/blob/2.2-develop/app/code/Magento/CatalogUrlRewrite/Observer/ProductProcessUrlRewriteSavingObserver.php)
   * [\Magento\CatalogUrlRewrite\Model\ProductUrlRewriteGenerator::generate](https://github.com/magento/magento2/blob/2.2-develop/app/code/Magento/CatalogUrlRewrite/Model/ProductUrlRewriteGenerator.php#L128)
   * deleteByData, replace
@@ -104,6 +106,8 @@ Category:
   * child category.url_path
 
 - event `catalog_category_save_after` - when changed (key, anchor, products)
+  * [CategoryProcessUrlRewriteSavingObserver](https://github.com/magento/magento2/blob/2.2-develop/app/code/Magento/CatalogUrlRewrite/Observer/CategoryProcessUrlRewriteSavingObserver.php#L90)
+  * [\Magento\CatalogUrlRewrite\Observer\UrlRewriteHandler::generateProductUrlRewrites](https://github.com/magento/magento2/blob/2.2-develop/app/code//Magento/CatalogUrlRewrite/Observer/UrlRewriteHandler.php#L124)
   * ... lots of logic