Example code for viewing PID values uses legacy format in ReadMe file

[tobesr]

The example code to view the PID values in the readme uses the old home assistant format. I have updated the format which can just be dropped into the readme file:

template:
    - sensor:
      - name: "PID Output"
        unit_of_measurement: "%"
        state: "{{ state_attr('climate.smart_thermostat_example', 'control_output') | float(0) }}"

      - name: "PID P"
        unit_of_measurement: "%"
        state: "{{ state_attr('climate.smart_thermostat_example', 'pid_p') | float(0) }}"        

      - name: "PID I"
        unit_of_measurement: "%"
        state: "{{ state_attr('climate.smart_thermostat_example', 'pid_i') | float(0) }}"

      - name: "PID D"
        unit_of_measurement: "%"
        state: "{{ state_attr('climate.smart_thermostat_example', 'pid_d') | float(0) }}"

      - name: "PID E"
        unit_of_measurement: "%"
        state: "{{ state_attr('climate.smart_thermostat_example', 'pid_e') | float(0) }}"