Update Docker install instructions $PWD containing spaces
Update Docker install instructions $PWD containing spaces

When current dir contains spaces,
-v $PWD/config:/etc/api-umbrella
won't expand correctly and command fails, as $PWD is not necessary in Docker command, we can just forget about it.
NREL/api-umbrella,apinf/api-umbrella,apinf/api-umbrella,NREL/api-umbrella,NREL/api-umbrella,apinf/api-umbrella,apinf/api-umbrella,apinf/api-umbrella,NREL/api-umbrella