feat: Implement the promoter event creation

- Promoter can now create an event in draft mode
- Place is found based on address and long/lat are automatically
  deducted from it
- Slug is forged using the *slug* npm package instead of custom code

db/migrate/20250823145902_create_events.rb

@@ -10,8 +10,12 @@ class CreateEvents < ActiveRecord::Migration[8.0]
       t.string :venue_address, null: false
       t.datetime :start_time
       t.datetime :end_time
+
+      # Latitude and longitude of the place
       t.decimal :latitude, precision: 10, scale: 6, null: false
       t.decimal :longitude, precision: 10, scale: 6, null: false
+
+      # Only admin or later premium promoters could select this
       t.boolean :featured, default: false, null: false
       t.references :user, null: false, foreign_key: false