Fix Homeassistant Lovelace configuration

[mboremski]

Thank you for your project!
More than 2000 coffes have been brewed with this (in openhab).
Now moving it to Homeassistant

I was struggeling while using the readme to implement it into Homeassistant.
These buttons where not working on the dashboard:

I found that you point to non existing entitys here:

I fixed this by using the buttons defined by senseo_wifi.yaml and making them pressable like so:

    card:
      type: entities
      entities:
        - type: buttons
          entities:
            - entity: button.senseowifi_brew_coffee_normal
              name: kleine Tasse brühen
              icon: mdi:coffee-to-go
              tap_action:
                action: call-service
                service: button.press
                service_data:
                  entity_id: button.senseowifi_brew_coffee_normal
            - entity: button.senseowifi_brew_coffee_double
              name: große Tasse brühen
              icon: mdi:coffee-to-go
              tap_action:
                action: call-service
                service: button.press
                service_data:
                  entity_id: button.senseowifi_brew_coffee_double

Maybe you can update the readme with this.

Could you maybe also give a clear hint to use packages to implement senseo_wifi.yaml?
As a new homeassistant-user I have been spreading the configs over my configuration.yaml befor I found the easy way in #41.