Create an empty `application.properties`

[Stéphane Nicoll]

A person on gitter got confused as they were starting with this and they have redis on a different host. Documentation mentions application.properties but the file doesn't exist here.

It would be nice if there was one. Perhaps with a few typical commented out properties?

[monotonewang]

https://docs.spring.io/spring-boot/docs/2.3.0.RELEASE/reference/html/appendix-application-properties.html#data-properties

[Jay Bryant]

The readme no longer mentions application.properties.