Add basic yaml examples

[mDubovsky]

For people not so versed in the esphome ecosystem it would be beneficial to add yaml examples such as (but not limited to):

• configuration for ethernet
• configuration for wifi
• 2 daisy chained modules
• basic functionality like double click / long press

This can be added to readme and/or wiki

[pilotak]

another option is to show is the gang switch intead of button

binary_sensor:
  - platform: gpio
    id: in1
    pin:
      pcf8574: in_hub1
      number: 7
      mode: INPUT
      inverted: True
    filters:
      - delayed_on: 3ms
      - delayed_off: 3ms
    on_press:
      then:
        - switch.turn_on: output1
    on_release:
      then:
        - switch.turn_off: output1