README.md in wicked_pdf-0.7.7 vs README.md in wicked_pdf-0.7.8

@@ -59,11 +59,11 @@
                    :cover                          => 'URL',
                    :dpi                            => 'dpi',
                    :encoding                       => 'TEXT',
                    :user_style_sheet               => 'URL',
                    :cookie                         => ['_session_id SESSION_ID'], # could be an array or a single string in a 'name value' format
-                   :post                           => ['query QUERY_PARAM'],    # could be an array or a single string in a 'name value' format
+                   :post                           => ['query QUERY_PARAM'],      # could be an array or a single string in a 'name value' format
                    :redirect_delay                 => NUMBER,
                    :zoom                           => FLOAT,
                    :page_offset                    => NUMBER,
                    :book                           => true,
                    :default_header                 => true,
@@ -75,10 +75,11 @@
                    :disable_external_links         => true,
                    :print_media_type               => true,
                    :disable_smart_shrinking        => true,
                    :use_xserver                    => true,
                    :no_background                  => true,
-                   :margin => {:top                => SIZE,                         # default 10 (mm)
+                   :extra                          => ''                        # directly inserted into the command to wkhtmltopdf
+                   :margin => {:top                => SIZE,                     # default 10 (mm)
                                :bottom             => SIZE,
                                :left               => SIZE,
                                :right              => SIZE},
                    :header => {:html => { :template => 'users/header.pdf.erb',  # use :template OR :url
                                           :layout   => 'pdf_plain.html',        # optional, use 'pdf_plain.html' for a pdf_plain.html.erb file, defaults to main layout