Introduce event categories

Closes #1056

Signed-off-by: Thomas Citharel <tcit@tcit.fr>

priv/repo/migrations/20220328153640_set_all_events_category_to_meeting.exs

@@ -0,0 +1,11 @@
+defmodule Mobilizon.Storage.Repo.Migrations.SetAllEventsCategoryToMeeting do
+  use Ecto.Migration
+
+  def up do
+    Ecto.Migration.execute("UPDATE events SET category = 'MEETING'")
+  end
+
+  def down do
+    Ecto.Migration.execute("UPDATE events SET category = 'meeting' WHERE category = 'MEETING'")
+  end
+end