Revert "Revert "rework recipe and upgrade kuma version""

This reverts commit 7897cae890.

.env.sample

@@ -10,6 +10,8 @@ DOMAIN=uptime-kuma.example.com
 SECRET_DB_PASSWORD_VERSION=v1
 SECRET_DB_ROOT_PASSWORD_VERSION=v1
 
-
-## Enable mariadb
+## Enable mariadb, otherwise sqlite will be used
 #COMPOSE_FILE="$COMPOSE_FILE:compose.mariadb.yml"
+
+# only for testing branches of uptime-kuma
+#UPTIME_KUMA_GH_REPO=<branch name>