Update index.md (#515)

Author: jukent

portal/index.md

@@ -71,14 +71,14 @@ Pythia Cookbooks are collections of more advanced and domain-specific example wo
 :::
 
 :::{card}
-:url: ./resource-gallery.md
+:url: https://projectpythia.org/resource-gallery/
 :header: The Resource Gallery
 :footer: Visit the Resource Gallery »
 
 There is a wealth of educational resources out there on the internet for learning
 Python and how to use it in the geosciences! We have attempted to gather together
 a curated and filterable list of these resources (including Pythia's own content)
-into our [Pythia Resource Gallery](/resource-gallery).
+into our [Pythia Resource Gallery](https://projectpythia.org/resource-gallery/).
 Click the link below to see a hand-picked selection of resources for learning at
 your own pace.
 :::