docs: build with clean URLs

[mrpollo]

Enable clean urls for vitepress builds

cc @hamishwillee please verify this is actually building the files as we need them, suposedly creating directories with index files so the urls are clean

[hamishwillee]

@mrpollo There is no way to test this locally because the live server always supports either clean or non-clean URLs. I did make the modification and test that. I also built the library locally and compared the output with cleanUrls: true - the content of the files is different, but all generated files have the same .html extension.

Upshot, I suspect that with the suggested change this might work, but it is hard to tell. We'll probably have to deploy and test.

[hamishwillee]

@mrpollo @dakejahl Just some follow on testing

What this change does is (I think) force Vitepress to open clean URLs by default and redirect to clean URLs by default. So if you open a sitebar you always get a clean URL, and if you enter https://docs.px4.io/main/en/flying/plan_safety_points.html it will redirect to https://docs.px4.io/main/en/flying/plan_safety_points

I tested this and it works. The other builds do not use clean URLs so if you open a sidebar they will still have .html extension. I don't think it matters - all the URLs work if you navigate to the site so no links are broken.

Thanks!

[mrpollo]

@hamishwillee i realized the behavior on older releases was going to be different, but it also looks like its not a big deal. However I do have better visibility into 404's in the server logs now that we moved away from github pages, i will keep an eye for issues.

[hamishwillee]

Great. I have made v1.16 match. I don't think this will be any kind of problem