Add holiday blog post hero images

Author: tildechris

content/blog/2021-01-22-holiday-surveys.Rmd

@@ -9,8 +9,8 @@ tags:
 summary: |
   How did Thanksgiving and Christmas affect travel, social, and preventative
   behaviors in the USA during the COVID-19 pandemic?
-heroImage: /blog/images/blog-lg-img_hello-world.jpg
-heroImageThumb: /blog/images/blog-thumb-img_hello-world.jpg
+heroImage: /blog/images/holiday-gathering.jpg
+heroImageThumb: /blog/images/holiday-gathering-small.jpg
 authors:
   - lmorinishi
   - kbarkume