New functionality to provide a sitemap_index.xml file for accounts with more than one microsite.

Additionally this fixes several bugs in shopserve:

  • Unpublished sites were still being served.
  • Fix for SCSS includes on relative paths in themes when operating in developer mode.
  • Crash when converting string to array in liquid.
  • Crash when converting bool to array in liquid.
  • Crash when slice filter first index is out of bounds in liquid.