IMP: ANCOM -> ANCOM-BC tutorial updates

[lizgehret]

Replaces ancom with ancombc in PD Mice and Moving Pictures tutorials.

[cherman2]

This looks really good to me @lizgehret. You do an incredible job of explaining ancom-bc

[gregcaporaso]

@lizgehret, this looks great!

I made a few little edits in the most recent commit.

1. "Why?" -> "Why might you expect this?" in the moving pics docs. Since it's not necessarily the case that there would be fewer differentially abundant genera than ASVs, I just felt like "Why might..." was a better way to ask this question.
2. 'donor + genotype' -> 'donor * genotype' - this aligns with how we run the anova earlier in the tutorial, and makes sense because donor and genotype could interact (apologies if I previously suggested using + here).

Also, in the multiple interfaces moving pictures tutorial, the filtering command is rendering strangely:

If you're good with my edits, this is good to merge once we get that rendering issue sorted out.

[gregcaporaso]

Just see my comment above about the filtering command rendering strangely. I don't need to review this again before merge. Thanks @lizgehret!

[lizgehret]

Thanks @gregcaporaso! Oh yeah, that does look weird - I'll render locally and see what's going on there!

[lizgehret]

If you're good with my edits, this is good to merge once we get that rendering issue sorted out.

Okay, so for posterity - this has been fixed, and now looks reasonable when rendered locally:

Once this passes on CI, I'll go ahead and merge. Thanks for the review @gregcaporaso!

[gregcaporaso]

Thanks @lizgehret!