* add specific docker network to allow gateway and subnet configuration
  * add separate location for pgAdmin in dev mode
  * add docker container names attribute in addition to service name
  * add websocket config to nginx.conf from nginx.raw
  * make network-name configurable

Signed-off-by: Daniel Einars <contact@dle.dev>

Restored the 'dbHost' variable and renamed the container names to end in '_CONT_NAME' rather than '_HOST'. Also added a note in the '.env' file that the dbHost and DB_CONT_NAME variables must match if you want to use the renamed DB container.

Looks like theres a bug with nested varibles for my docker-compose. Avoiding it by dropping the SERVICE_PREFIX variable.

Added a rename command to the Makefile that regenerates the docker-compose files and the nginx.conf file to enable changing the names of the containers.

added comment about removing 'db' container if using your own db server.