2026 Intro scRNA-seq workshop fixes

This issue contains items we found to fix while teaching these materials.

h/t to a participant for kicking us off by finding a typo!

> FYI, there's a small type in the notebook, line 49, spelling of hodgkins: "We have included some of these in the `data/hodkins/cellranger` directory, including the `web_summary.html` file that includes some similar QC statistics to those we generated with `alevinQC`."

Search the workshop notebooks for the text around line 49, especially the reference to data/hodkins/cellranger/web_summary.html and alevinQC. Correct the reported spelling typo in that notebook and verify that the surrounding text and referenced path are consistent.

Written by the indexing model from the issue text.