add ads tag to listings, title change for listing, some cleanup

_config/filters.js

@@ -60,7 +60,7 @@ export default function(eleventyConfig) {
 
 	/* Filter out structural tags */
 	eleventyConfig.addFilter("removeCoreTags", (tags) => {
-		return tags.filter(tag => ["all"].indexOf(tag) === -1);
+		return tags.filter(tag => ["all", "ads"].indexOf(tag) === -1);
 	});
 
 	/* What it says on the tin */