Generate table of all databases and schema with a single psql command In PostgreSQL is it possible to generate a list of all databases and all schema with a single psql command?

To be concrete, let me provide an example. 

I have two databases in a PotgreSQL database cluster: accounts and people. In the accounts database there are these schema  (beyond the default): hr and finance. In the people database there are these schema (beyond the default): hr, admin, backup. 

Is there a single psql command I can run that generates results something like this:

database | schema
-----------------
accounts |  hr
accounts |  finance
people   |  hr
people   |  admin
people   |  backup


Or is the only way to generate this information to connect multiple times and run separate queries?
In PostgreSQL is it possible to generate a list of all databases and
  all schema with a single psql command?


No. The list of schemas of a database is private to that database and cannot be obtained without being connected to it.
The list of databases is available with \l or select * from pg_database.