Added enhanced slides example.

[middle-way-approach]

1. It is now possible to format the slide content. The format can be specified in the data section.
   DATA color, x-position, y-position, text

2. You can now navigate between the slides via the arrow keys.

3. An indicator is displayed in the lower right corner, which shows the current slide and the maximum number of slides.

4. The example shows the usage of a custom type that is stored in a two-dimensional array.

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[middle-way-approach]

I signed it!

[googlebot]

CLAs look good, thanks!

[flagxor]

lgtm

[flagxor]

Thanks for the contribution!