Update correct lines in Github repository

Fix lines docs in Github repository

Author: agoede

docs/documentation/overview/responsiveness.html

@@ -40,7 +40,7 @@
 
 {% include elements/anchor.html name="Breakpoints" %}
 
-{% assign variables_file_url = "/blob/master/sass/utilities/initial-variables.sass#L46,L57" | prepend: site.data.meta.github %}
+{% assign variables_file_url = "/blob/master/sass/utilities/initial-variables.sass#L56,L64" | prepend: site.data.meta.github %}
 {% assign mixins_file_url = "/blob/master/sass/utilities/mixins.sass#L81,L129" | prepend: site.data.meta.github %}
 
 <div class="content">