feat: display inversion command

[rafaltrojniak]

Add display inversion command.
Add inversion example with changing screen inversion
without redrawing it (basically blinking the screen).

[UncleGrumpy]

This is a nice addition. There are definitely times this can be a very useful feature.

I should have been a little more clear. We like for the examples to be a simple demonstration of a single feature. So rather than add to or modify the existing ssd1306_example, it would be better to add a second example (ssd1306_inversion_example) that just demonstrates the inversion feature you have added. This makes it easier for newcomers to see how a particular feature works without getting overwhelmed by a more complex application. And perhaps for simplicity, rather than involve the gpio driver, maybe invert the display in a recursive function that just flips the direction every 5000 milliseconds or so.

We do also welcome more complex application examples, but we call these demos, and usually add them to a separate folder like we do in the atomvm_examples repo.

[rafaltrojniak]

Thanks @UncleGrumpy for the feedback.
I have moved the example to separate new project under examples directory.

[UncleGrumpy]

You should probably update the commit message to reflect the changes you made to the example of the inversion feature. ;-)