readme sample code needs updated

[FoamyGuy]

The example in the readme is using this function clue.display_clue_data() but it does not seem to exist any more. This example from in the repo is essentially the same thing. It's using clue.simple_text_display() and it works correctly as far as I can tell. I can work on making a PR to change the readme to match the example script.

[caternuson]

Left overs from a function name change. Looks like it also shows up in doc string:

Adafruit_CircuitPython_CLUE$ grep -i -r display_clue_data
adafruit_clue.py:        ``clue_data = display_clue_data()`` then ``clue_data[0].text = clue.proximity`` must be
adafruit_clue.py:        .. image :: ../docs/_static/display_clue_data.jpg
README.rst:    clue_data = clue.display_clue_data(title="CLUE Sensor Data!", title_scale=2, num_lines=15)

[FoamyGuy]

#25 resolves this issue