update landing page layout to pipe intro frontmatter text through markdownify filter - closes #156
update to product layout to pull linked docs from absolute URL rather than /assets/docs within the site dir - closes #154
show all products on resource search page. also created include file for featured products block on news page - closes #153
update list of press releases to be reverse chronological by date - closes #152
update calls to action to use "link" variable for href instead of the literal URL of the CTA object - closes #151
include subhead and cta_button variables in page header - #149
updates to subnav menu generation to only show menu if there is more than one link in the menu - #149
moving parent subnav menu item code into subnav.html and updating references in layouts to only include subnav.html - closes #149
update background color of parent subnav menu item - #148