feat: add .env.example for all

src/mongodb-replicaset/.env.example

@@ -0,0 +1,17 @@
+# MongoDB Version
+MONGO_VERSION=8.0.13
+
+# MongoDB root credentials
+MONGO_INITDB_ROOT_USERNAME=root
+MONGO_INITDB_ROOT_PASSWORD=password
+
+# Initial database name
+MONGO_INITDB_DATABASE=admin
+
+# Replica set name
+MONGO_REPLICA_SET_NAME=rs0
+
+# MongoDB ports for each replica
+MONGO_PORT_OVERRIDE_1=27017
+MONGO_PORT_OVERRIDE_2=27018
+MONGO_PORT_OVERRIDE_3=27019