Notebooks refer to future notebooks

[wtgee]

The Combine spectra misaligned notebook states to "We'll conduct the same steps as we did in our previous tutorial on masking." but proceeds the masking notebook in the tutorial list and documentation walk-through.

The same happens in the Flattening with a SG filter notebook referring to the Masking Plus.

This may or may not be an issue but is a little odd when doing going through the documentation in order.

I feel bad not just submitting quick PRs for these but as reviewer I'm not supposed to, sorry.

[gully]

Thank you again for this feedback, tutorials are the primary entry point for newcomers and they should logically relate to each other.

We have overhauled the entire tutorial landing page which makes the ordering less important, with easier visual cues for folks to see what the tutorial may contain. I rewrote some of the prose and removed previous/future references in favor of concepts. The tutorials could probably use an overhaul or maybe a combination of some related notebooks, but overall they are better than before.

Thanks again for your feedback on this!