[Docs] import paths in register layout's programming guide

[soodoshll]

In https://nvidia.github.io/tilus/programming-guides/layout-system/register-layout.html,
operations like spatial are not longer able to be found in the given path. Same as visualize_layout

[soodoshll]

And there seems to be no more repeat?

[yaoyaoding]

Thanks @soodoshll !

Since the documentation is for v0.1.1, there are some changes in the codebase so there might be some mismatch. These functions are now in namespace tilus.ir.layout.ops. The repeat layout is renamed to local, to follow the paper.

[yaoyaoding]

Do you mind submitting a PR to update this part of docs?

[yaoyaoding]

We can have some different versions of documentation like latest for nightly built, stable for latest release, and v0.1.1 etc for specific versions. I have an issue for this feature request #67.