Missing argument in resize_image docs (#778)

docs/content/documentation/content/image-processing/index.md

@@ -9,7 +9,7 @@ which is available in template code as well as in shortcodes.
 The function usage is as follows:
 
 ```jinja2
-resize_image(path, width, height, op, quality)
+resize_image(path, width, height, op, format, quality)
 ```
 
 ### Arguments
@@ -150,4 +150,4 @@ Here is the result:
 ## Get image size
 
 Sometimes when building a gallery it is useful to know the dimensions of each asset.  You can get this information with
-[get_image_metadata](@/documentation/templates/overview.md#get-image-metadata) 
+[get_image_metadata](@/documentation/templates/overview.md#get-image-metadata)