Add SkySQL r2dbc connection string example

Author: alejandro-du

reactive-service/src/main/resources/application.properties

@@ -5,4 +5,10 @@ spring.r2dbc.url=r2dbc:mariadb://localhost:3306/wordle
 spring.r2dbc.username=user
 spring.r2dbc.password=password
 spring.r2dbc.pool.max-size=10
-spring.r2dbc.pool.max-create-connection-time=10s
+spring.r2dbc.pool.max-create-connection-time=10s
+
+# If you are using MariaDB SkySQL (https://mariadb.com/products/skysql),
+# enable SSL and specify the path to the CA chain file that you can download
+# from the SkySQL Portal (https://cloud.mariadb.com):
+#
+# spring.r2dbc.url=r2dbc:mariadb://demo-db0000xxxx.mdb000xxxx.db.skysql.net:5047/reactive-demo?sslMode=VERIFY_CA&serverSslCert=/path/to/skysql_chain.pem