fixing url link

Author: shimwell

README.md

@@ -12,4 +12,4 @@ Then build and host the site locally with
 myst start
 ```
 
-[link to live site](https://opnmc-dev.github.io/openmc.org/)
+[link to live site](https://openmc-dev.github.io/openmc.org//)

myst.yml

@@ -21,7 +21,7 @@ site:
   - title: Discussion Forum
     url: https://openmc.discourse.group/
   - title: Cross Sections
-    url: /openmc.org/cross_sections
+    url: openmc.org/cross_sections
   - title: Depletion Chains
-    url: /openmc.org/depletion_chains
+    url: openmc.org/depletion_chains
   domains: []