Merge pull request #470 from antograssiot/missing-filters

Add missing core filters to the menu

Author: soyuka

index.md

@@ -28,10 +28,12 @@
             1.  [Managing `null` Values](core/filters.md#managing-null-values)
         3.  [Boolean Filter](core/filters.md#boolean-filter)
         4.  [Numeric Filter](core/filters.md#numeric-filter)
-        5.  [Order filter](core/filters.md#order-filter)
+        5.  [Range Filter](core/filters.md#range-filter)
+        6.  [Exists Filter](core/filters.md#exists-filter)
+        7.  [Order filter](core/filters.md#order-filter)
             1.  [Using a Custom Order Query Parameter Name](core/filters.md#using-a-custom-order-query-parameter-name)
-        6.  [Filtering on Nested Properties](core/filters.md#filtering-on-nested-properties)
-        7.  [Enabling a Filter for All Properties of a Resource](core/filters.md#enabling-a-filter-for-all-properties-of-a-resource)
+        8.  [Filtering on Nested Properties](core/filters.md#filtering-on-nested-properties)
+        9.  [Enabling a Filter for All Properties of a Resource](core/filters.md#enabling-a-filter-for-all-properties-of-a-resource)
     2.  [Serializer Filters](core/filters.md#serializer-filters)
         1.  [Group Filter](core/filters.md#group-filter)
         2.  [Property Filter](core/filters.md#property-filter)