Add callout about Clerk auto-deleting empty organizations

[alexisintech]

Important

🔎 Previews:

• https://clerk.com/docs/pr/1550/organizations/overview#create-an-organization

Explanation:

Linear ticket reads:

When assisting a user, I learned that Clerk automatically deletes orgs that have no members in them. This can be alarming to a user who may be creating orgs without members for a certain use-case. To minimize confusion, we would like to add a callout / warning in the docs so users can be aware of this, and also so support has somewhere in the docs to point to if users do write in about this behavior. I'm not entirely sure where this should live so I wanted to make a linear tix for this

In the Slack thread linked in the Linear ticket, Mary mentioned:

we have a regular running job that deletes "orphan" orgs (orgs with no members) every hour

THIS PR:

• Adds this information to the docs

[github-actions]

Hey, here’s your docs preview: https://clerk.com/docs/pr/1550