You must include a catalog skeleton body inside your custom disaster if you want it to be available on the catalog, you can submit your disaster on the in the #disaster-submission channel! This is how your YAML should look:
# * Your settings skeleton body with info about the disaster
settings:
# Settings info
# * Your core body for defining events and actions inside levels
core:
# Core info
# Your custom items skeleton body if you decided to create one for your disaster
items:
# Custom items
# Your custom entities skeleton body if you have custom mobs in your disaster
entities:
# Custom entities
# * This is how you define a catalog section for your disaster
catalog:
# Item that will be displayed for your disaster in the catalog in-game gui
item: 'lava_bucket'
# A short description of your disaster
description: '&eExample disaster to show you how to create custom disasters'
# Your name for credit
author: 'JewishBanana'