Reduce intro preamble

[widdowquinn]

After the 2024 presentation, in discussion with @mafeeney we considered reducing the number of slides we showed summarising students' responses to the figures at the start of the presentation.

We also had an idea to enhance this section by…

1. showing the same data as several visualisations, to demonstrate their strengths and weaknesses
2. building a visualisation from very minimalist, to try to enhance the figure, showing a process by which we can improve a visualisation