minor bug on Tutorial docs

[stevehan00]

Describe the issue

The links for "Next Tutorial" below the page in Tutorials does not work well because the link should be linked to *.html but it has caused '404 not found' by loading *.md files

Minimal code example

No response

Files required to run the code

No response

Expected behavior

"*.html" links should be loaded

BlenderProc version

Github main bracnch

[cornerfarmer]

Thanks for the hint!

[stevehan00]

Thank you :)