Update README with downloading HPO data

[apraga]

Hi,

Just discovered your project and it looks great ! I was a bit confused about downloading the data, so here's a pull request to make it hopefully more clear on the README.

Thanks,

[anergictcell]

Great suggestions, thanks for the PR. I'll happily merge it, but the CICD has some minor errors.
They are not caused your changes, but are caused by the strict clippy and fmt rules I defined. The rust version was updated and apparently has new formatting requirements for rust fmt.

I am traveling without my laptop and can't make those fixes myself unfortunately. You could integrate them into your PR or wait for me to do it next week.

Also you might have to change the code blocks you added to the readme to no_run, otherwise the automated tests will fail.
Can you run

cargo fmt
cargo clippy
cargo test

Just to ensure it all works.

Sorry to be so pedantic, even for such a minor fix.
Thanks for your help

[apraga]

Hi,
cargo clippy complained about panics not documentated and a few other things. I've added some fixes to make it happy again.

Edit: I cannot reproduce the build errors locally. Any ideas ?

[anergictcell]

It seems that clippy also became more strict. Of you don't feel confide t implementing the suggested fixes, I will do that this weekend and merge your changes.
As nice as automated check for merging are, they can really become annoying for projects that don't have actual continuous pushes ;)