add details on environment variables (#41)

* add details on environment variables

01_getting-started/03_configuration/03_env-variables.md

@@ -4,8 +4,21 @@ title: Environment variables
 nav_order: 3
 grand_parent: Getting started
 parent: Configuration
-last_modified_date: 20-10-2021 13:00
+last_modified_date: 18-10-2023 13:00
 permalink: /getting-started/configuration/env-variables/
 ---
 
-# Environment variables
+# Environment variables
+
+Masa CMS can be configured using environment variables. When hosting Masa CMS in a Docker container on a public cloud provider, this comes in very useful.
+
+## Available variables
+
+All Masa CMS settings are available as environment variables using the following format: `MURA_{setting}`, for example `MURA_APPRELOADKEY`.
+
+[List of available settings](/getting-started/configuration/configuration-file/)
+
+Additionally, there are some more environment variables that allow you to configure your Masa CMS environment:
+
+* MURA_ADMIN_USERNAME
+* MURA_ADMIN_PASSWORD