Updated comments and order in .env.example (#44)

- The main meaningful change here is commenting the GHOST_VERSION variable
- I've also reordered the blocks to prioritise things in the documented setup flow
- Made various changes to the comments for clarity

.env.example

@@ -1,15 +1,13 @@
 # Use the below flags to enable the Analytics or ActivityPub containers as well
 # COMPOSE_PROFILES=analytics,activitypub
 
-# Which Ghost version to run
-GHOST_VERSION=6.0.0-rc.2-alpine
-
-# Public domain Ghost is going to run on
+# Ghost domain
+# Custom public domain Ghost will run on
 DOMAIN=example.com
 
-# If you have Ghost Admin setup on a separate domain
-# uncomment the below along with the corresponding block
-# in your Caddyfile
+# Ghost Admin domain
+# If you have Ghost Admin setup on a separate domain uncomment the line below and add the domain 
+# You also need to uncomment the corresponding block in your Caddyfile
 # ADMIN_DOMAIN=
 
 # Database settings
@@ -17,28 +15,17 @@ DATABASE_ROOT_PASSWORD=reallysecurerootpassword
 # DATABASE_USER=optionalusername
 DATABASE_PASSWORD=ghostpassword
 
-# Port Ghost should listen on
-# You should only need to edit this if you want to host
-# multiple sites on the same server
-# GHOST_PORT=2368
-
 # ActivityPub
-# If you'd prefer to self-host ActivityPub yourself uncomment the below line
+# If you'd prefer to self-host ActivityPub yourself uncomment the line below
 # ACTIVITYPUB_TARGET=activitypub:8080
 
 # Tinybird configuration
+# If you want to run Analytics, paste the output from `docker compose run --rm tinybird-login get-tokens` below
 # TINYBIRD_API_URL=https://api.tinybird.co
 # TINYBIRD_TRACKER_TOKEN=p.eyJxxxxx
 # TINYBIRD_ADMIN_TOKEN=p.eyJxxxxx
 # TINYBIRD_WORKSPACE_ID=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
 
-# Data locations
-# Location to store uploaded data
-UPLOAD_LOCATION=./data/ghost
-
-# Location for database data
-MYSQL_DATA_LOCATION=./data/mysql
-
 # Ghost configuration (https://ghost.org/docs/config/)
 
 # SMTP Email (https://ghost.org/docs/config/#mail)
@@ -50,3 +37,22 @@ mail__options__port=465
 mail__options__secure=true
 mail__options__auth__user=postmaster@example.com
 mail__options__auth__pass=1234567890
+
+# Advanced customizations
+
+# Force Ghost version 
+# You should only do this if you need to pin a specific version
+# The update commands won't work
+# GHOST_VERSION=6.0.0-rc.2-alpine
+
+# Port Ghost should listen on
+# You should only need to edit this if you want to host
+# multiple sites on the same server
+# GHOST_PORT=2368
+
+# Data locations
+# Location to store uploaded data
+UPLOAD_LOCATION=./data/ghost
+
+# Location for database data
+MYSQL_DATA_LOCATION=./data/mysql