Documentation: Note that environment variables for the configuration templates should always be set when using the all-in-one script

[loudonlune]

Related: #179

It should be highlighted in the user documentation for the all-in-one installer that the user must set certain environment variables when using the all-in-one script (e.g. AGBOT_TOKEN) or the deployment will break. It is also relevant to note that any other custom settings used in the configuration templates (e.g. internal port addresses, container specific settings like AGBOT_AGREEMENT_BATCH_SIZE) will not persist if they are not set.