message: make psql instructions copy/paste-able
  this was really annoying me
diff: @@ -167,9 +167,7 @@ If you want to explore or edit database manually, you can connect to the databas
  with the `psql` command.
  ```sh
  -# this will print the name of the container it starts
  -docker-compose run -d db
  -docker exec -it <the container name goes here> psql -U cratesfyi
  +docker exec -it "$(docker-compose run -d db && sleep 1)" psql -U cratesfyi
  ```
  The database contains a blacklist of crates that should not be built.
  