Changed stack.env to use macros

Docker/immich/stack.env

@@ -1,21 +1,21 @@
 # You can find documentation for all the supported env variables at https://immich.app/docs/install/environment-variables
 
 # The location where your uploaded files are stored
-UPLOAD_LOCATION=./library
+UPLOAD_LOCATION=${UPLOAD_LOCATION}
 # The location where your database files are stored
-DB_DATA_LOCATION=./postgres
+DB_DATA_LOCATION=${DB_DATA_LOCATION}
 
 # To set a timezone, uncomment the next line and change Etc/UTC to a TZ identifier from this list: https://en.wikipedia.org/wiki/List_of_tz_database_time_zones#List
 # TZ=Etc/UTC
 
 # The Immich version to use. You can pin this to a specific version like "v1.71.0"
-IMMICH_VERSION=release
+IMMICH_VERSION=${IMMICH_VERSION:-release}
 
 # Connection secret for postgres. You should change it to a random password
 # Please use only the characters `A-Za-z0-9`, without special characters or spaces
-DB_PASSWORD=postgres
+DB_PASSWORD=${DB_PASSWORD}
 
 # The values below this line do not need to be changed
 ###################################################################################
-DB_USERNAME=postgres
-DB_DATABASE_NAME=immich
+DB_USERNAME=${DB_USERNAME}
+DB_DATABASE_NAME=${DB_DATABASE_NAME}