fixed typos in comments / API docs

system/src/Grav/Common/Page/Medium/ImageMedium.php

@@ -232,7 +232,7 @@ class ImageMedium extends Medium
     }
 
     /**
-     * Allows the ability to override the Inmage's Pretty name stored in cache
+     * Allows the ability to override the image's pretty name stored in cache
      *
      * @param string $name
      */

system/src/Grav/Common/Twig/TwigExtension.php

@@ -455,7 +455,7 @@ class TwigExtension extends \Twig_Extension implements \Twig_Extension_GlobalsIn
     }
 
     /**
-     * Gets a human readable output for cron sytnax
+     * Gets a human readable output for cron syntax
      *
      * @param $at
      * @return string

system/src/Grav/Framework/Collection/AbstractIndexCollection.php

@@ -437,7 +437,7 @@ abstract class AbstractIndexCollection implements CollectionInterface
     }
 
     /**
-     * Implementes JsonSerializable interface.
+     * Implements JsonSerializable interface.
      *
      * @return array
      */

system/src/Grav/Framework/Collection/ArrayCollection.php

@@ -84,7 +84,7 @@ class ArrayCollection extends BaseArrayCollection implements CollectionInterface
     }
 
     /**
-     * Implementes JsonSerializable interface.
+     * Implements JsonSerializable interface.
      *
      * @return array
      */