Revert "Add ubuntu screen file (#7094)"

Revert “Add ubuntu screen file (#7094)”

This reverts commit ddb87e2759392c1ca0f047c15ca5979df8549a12.

I merged this by mistake, prefer this documentation on meta.

diff --git a/docs/ubuntu.screen b/docs/ubuntu.screen
deleted file mode 100644
index b272c8a..0000000
--- a/docs/ubuntu.screen
+++ /dev/null
@@ -1,18 +0,0 @@
-# GNU screen configuration file for Discourse Ubuntu development
-# Start up your development instance in detached mode:
-#   screen -d -m -c docs/ubuntu.screen
-# Start in attached mode:
-# screen -m -c docs/ubuntu.screen
-# commands that exit hang around until you hit 'k' to kill or 'r' to restart
-zombie kr
-screen -t rails_s 0 bash -c 'echo Starting rails server...;  cd ~/discourse; bundle exec rails s -b'
-screen -t rails_c 1 bash -c 'echo Starting rails console...; cd ~/discourse; bundle exec rails c'
-screen -t sidekiq 2 bash -c 'echo Starting sidekiq...;       cd ~/discourse; bundle exec sidekiq -l log/sidekiq.log'
-screen -t mail    3 bash -c 'echo Starting mailcatcher...;   cd ~/discourse; mailcatcher --http-ip'
-screen -t bash    4 bash
-scrollback 50000

GitHub sha: 80767080