Add RailsConf CFP 2024 (#575)

Author: andycroll

_data/conferences.yml

@@ -129,7 +129,7 @@
   twitter: rubyconfuruguay
   video_link: https://www.youtube.com/playlist?list=PLxx5qlTQCf0zx-DIFVHlftznHExI7ONEV
 
-- name: 'RubyMotion #inspect'
+- name: "RubyMotion #inspect"
   location: San Francisco, CA
   start_date: 2014-05-28
   end_date: 2014-05-29
@@ -1381,7 +1381,7 @@
   twitter: utrubyhack
   video_link: https://confreaks.tv/events/rubyhack2018
 
-- name: 'Madison+ Ruby: Chicago'
+- name: "Madison+ Ruby: Chicago"
   location: Chicago, Illinois
   start_date: 2018-05-10
   end_date: 2018-05-11
@@ -2481,6 +2481,9 @@
   url: https://www.railsconf.com
   twitter: railsconf
   mastodon: https://ruby.social/@railsconf
+  cfp_phrase: CFP closes
+  cfp_date: 2024-02-13
+  cfp_link: https://sessionize.com/railsconf2024
 
 - name: RubyKaigi 2024
   location: Naha, Okinawa, Japan