add listmonk app

modules/apps/listmonk/.env.example

@@ -0,0 +1,20 @@
+# Environment files
+ENV_FILE_LOCATION=/opt/environment/.env
+
+# Application specifics
+LISTMONK_BINARY=/usr/local/bin/listmonk
+LISTMONK_VERSION=6.0.0
+LISTMONK_CONFIG=/home/listmonk/config.toml
+DB_USER=listmonk
+DB_PASS=
+DB_NAME=listmonk
+LISTMONK_ADMIN_PASSWORD=
+LISTMONK_ADMIN_USER=admin
+
+# VM
+USERNAME=listmonk
+
+# Backup specifics
+SERVICE_BACKUPS_DIR=/backups/listmonk
+SERVICE_BACKUPS_PREFIX=listmonk-dump
+SERVICE_BACKUPS_EXTENSION=sql