docs: change table border colors

Author: RalphHightower

_sass/minima/skins/auto.scss

@@ -31,8 +31,8 @@ $lm-border-color-03:       $lm-brand-color-dark !default;
 $lm-table-text-color:      #73000a !default;
 $lm-table-zebra-color:     #fff2e3 !default;
 $lm-table-header-bg-color: #fff2e3 !default;
-$lm-table-header-border:   #fff2e3 !default;
-$lm-table-border-color:    #fff2e3 !default;
+$lm-table-header-border:   #73000a !default;
+$lm-table-border-color:    #73000a default;
 
 
 // Syntax highlighting styles should be adjusted appropriately for every "skin"