Add Blue Ridge Ruby 2026 (ruby-conferences#1250)

Author: jeremysmithco

_data/conferences.yml

@@ -3278,6 +3278,15 @@
   mastodon: https://ruby.social/@rubykaigi
   announced_on: 2025-04-18
 
+- name: Blue Ridge Ruby 2026
+  location: Asheville, NC
+  start_date: 2026-04-30
+  end_date: 2026-05-01
+  url: https://blueridgeruby.com
+  twitter: blueridgeruby
+  mastodon: https://ruby.social/@blueridgeruby
+  announced_on: 2025-12-12
+
 - name: Rubycon 2026
   location: Rimini, Italy
   start_date: 2026-05-08