Add Helvetic Ruby 2024 (#561)

Author: DoodlingDev

_data/conferences.yml

@@ -2560,3 +2560,11 @@
   end_date: 2024-10-18
   url: https://www.rubyfuza.org
   twitter: rubyfuza
+
+- name: Helvetic Ruby 2024
+  location: Zurich, Switzerland
+  start_date: 2024-05-17
+  end_date: 2024-05-17
+  url: https://helvetic-ruby.ch
+  twitter: helvetic_ruby
+  mastodon: https://ruby.social/@helvetic_ruby