Update images/gifs

[zoccoler]

Some images/gifs are lacking the new "Reset" button name:

• https://biapol.github.io/napari-clusters-plotter/usage/plotter_widget.html (here the text also needs update)

[zoccoler]

Also the tracking sample data needs update to the new scale: https://biapol.github.io/napari-clusters-plotter/examples/sample_data.html