Removed additional slash in primer nav (#475)

* Removed additional slash in primer nav

* Added changeset

Co-authored-by: Joshua Bowden <[email protected]>

Author: JoshBowdenConcepts

.changeset/stupid-bottles-agree.md

@@ -0,0 +1,5 @@
+---
+'@primer/gatsby-theme-doctocat': patch
+---
+
+Adding Primer Brand link to the main navigation

theme/src/primer-nav.yml

@@ -21,7 +21,7 @@
     - title: React
       url: https://primer.style/react
     - title: React Brand
-      url: https://primer.style/brand/
+      url: https://primer.style/brand
     - title: ViewComponents
       url: https://primer.style/view-components
 - title: Contribute