How to migrate Identity users from MVC5 to ASP.NET Core

See [this Stack Overflow](https://stackoverflow.com/a/57074910/2263507) question.

This article doesn't describe how to migrate anything. Migration of 'Identity' implies migration of data, but this article doesn't discuss that at all.

There's a package AspNetCoreCompat intended to help with that, but no documentation for it. https://github.com/aspnet/Identity/issues/2043

Some information about how to migrate the schema would be very useful. There is a similar article for Membership > Identity which contains SQL but this article has none.

## EDIT by @Rick-Anderson
2,500 PV per month, but important customers.
Additional issues:

* #19206

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#### Document Details

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* ID: db6772c4-1017-5e86-8045-8849b5dd1ad7
* Version Independent ID: bcb8d6b2-f38a-ac10-d3f2-69d4223bfd72
* Content: [Migrate Authentication and Identity to ASP.NET Core](https://docs.microsoft.com/en-us/aspnet/core/migration/identity?view=aspnetcore-2.1)
* Content Source: [aspnetcore/migration/identity.md](https://github.com/aspnet/Docs/blob/master/aspnetcore/migration/identity.md)
* Product: **aspnet-core**
* GitHub Login: @ardalis
* Microsoft Alias: **riande**