Add to readme instructions on restoring DB

[ghost]

Restores backup taken by pg_dump

Run in first terminal window (with or without -d, as you prefer, just make sure it's running):

COMPRESS_ENABLED=1 docker compose -f docker-compose.dev.yml up

Run in second terminal window:

docker compose -f docker-compose.dev.yml exec web psql -h postgres -U postgres

In Postgres shell:

create database temp;
(If it already exists that's fine, carry on)
\connect temp
drop database postgres;
create database postgres;
\q

Back on command line:

docker compose -f docker-compose.dev.yml exec web pg_restore -v -h postgres -U postgres -d postgres /usr/src/app/filename.dump 

At the end, a whole range of "role ?? does not exist" errors are fine.

[jarofgreen]

After running up, wait till services fully up and all DB migrations run.

If you see ERROR: database "postgres" is being accessed by other users errors that could be it.