Fix missing documentation reference for localstack module (#710)

Author: djakielski

mkdocs.yml

@@ -47,12 +47,13 @@ nav:
       - Elasticsearch: modules/elasticsearch.md
       - HiveMQ: modules/hivemq.md
       - Kafka: modules/kafka.md
+      - Localstack: modules/localstack.md
       - MongoDB: modules/mongodb.md
-      - MySQL: modules/mysql.md
       - MSSQLServer: modules/mssqlserver.md
+      - MySQL: modules/mysql.md
       - Nats: modules/nats.md
       - Neo4J: modules/neo4j.md
       - PostgreSQL: modules/postgresql.md
-      - Selenium: modules/selenium.md
       - Redis: modules/redis.md
+      - Selenium: modules/selenium.md
   - Configuration: configuration.md