docs: Update sort-keys options properties count

The current count is incorrect (3), as there are four items.
Avoid needing to update this with making the text more generic.

docs/src/rules/sort-keys.md

@@ -85,7 +85,7 @@ The 1st option is `"asc"` or `"desc"`.
 * `"asc"` (default) - enforce properties to be in ascending order.
 * `"desc"` - enforce properties to be in descending order.
 
-The 2nd option is an object which has 3 properties.
+The 2nd option is an object which has the following properties.
 
 * `caseSensitive` - if `true`, enforce properties to be in case-sensitive order. Default is `true`.
 * `minKeys` - Specifies the minimum number of keys that an object should have in order for the object's unsorted keys to produce an error. Default is `2`, which means by default all objects with unsorted keys will result in lint errors.