Replace New research guide link with old data guide link. New guide i…

…ncomplete.

index.html

@@ -74,7 +74,7 @@ <h2 class="text-4xl">Datasets</h2>
       {% include components/content-cta.html
         header = "Getting Started with NCCS Data"
         description = "Learn more about the NCCS data series through the research handbook."
-        ctaUrl = 'https://urbaninstitute.github.io/nccs-handbook/intro.html'
+        ctaUrl = 'https://nccs-data.urban.org/NCCS-data-guide.pdf'
         ctaText = "NCCS Research Guide"
         style = "dark"
       %}