Ability to share wiki by name#293

Allow users to share a wiki by name.

Examples:
docs.mywebsite.com/my-wiki
docs.mywebsite.com/my-project

This would be available as a custom domain or subdomain feature.

Job to be done:
When I want to share my wiki
I want to be able to share it with the wiki name as the url path
So it is easy to remember

Somewhat related: https://ynaw.nolt.io/288