improve report generation

[bpurinton]

Inspiration here: GlacioHack/xdem#569

Need to get away from markdown-pdf

cc @rhugonnet, if you find any more useful information or links.

[bpurinton]

via slack:

I think the link I had to an example report from demcompare is gone, because we use free Slack and it's been longer than 3 months 😅
But it looks like they make it easy to generate one in their usage example in the README: https://github.com/CNES/demcompare/tree/master?tab=readme-ov-file#usage if you want to have a look (even though I see an issue opened CNES/demcompare#5, hopefully that doesn't happen for you; avoiding Python 3.12 or higher is probably for the best)