chore(showcase): Add OnTravelDiary to list of sites (#25247)

* chore(sites): Add OnTravelDiary to list of sites

* chore: format

* Update docs/sites.yml

Co-authored-by: gatsbybot <mathews.kyle+gatsbybot@gmail.com>
Co-authored-by: Marcy Sutton <marcy@gatsbyjs.com>

Author: 3 people

docs/sites.yml

@@ -11234,6 +11234,18 @@
   built_by: Shion Honda
   built_by_url: https://twitter.com/shion_honda
   featured: false
+- title: Travel Diary - Your Digital Travelogue
+  main_url: https://ontraveldiary.com
+  url: https://ontraveldiary.com
+  description: >
+    An open to all digital platform for avid travelers to share their trips and photos with the world.
+  categories:
+    - Blog
+    - Travel
+    - Community
+  built_by: Draftbox
+  built_by_url: https://draftbox.co
+  featured: false
 - title: Ellington Hammond
   main_url: https://ellingtonhammond.com
   url: https://ellingtonhammond.com