[FR] Ability for users to specify server/base URL

[sserrata]

Is your feature request related to a problem?

There are some product APIs that generate a unique base URL per customer/tenant, which is not something we could know or predict ahead of time.

Describe the solution you'd like

The ability for users to manually type in their API base URL (server).

Describe alternatives you've considered

n/a

Additional context

Generated code samples directly reference the base URL. One consideration would be how to persist the custom base URL throughout the session or in localStorage.