[MIGRATE] Comp bio background

[NatalieZelenka]

• [x] figures
• [x] citations (done except in GO and summary sections)
• [x] math/latex
• [x] cross-refs
• [x] TODOs
• [x] epigraphs
• [x] title

[NatalieZelenka]

I'm doing this work on the compbio branch.

At the moment (most recent commit 4670ab39a), I am just adding in the text - I have done a fair amount of restructuring this chapter (as agreed with Oliver a really long time ago), and I'm much happier with the new structure, although it will need a lot of tidying. I've added a load of TODOs which will hopefully help me with that tidying.

So far, I have added just the text from the original compbio background (section 1.3 from the google drive). The next thing to do is to "translate" it to markdown (especially the table, but also the figures, the epigraphs, etc) and to add the citations, etc. Then I need to add the reproducibility bits from what is Chapter 5 in the google drive and do the same.

[NatalieZelenka]

I haven't added in the original work yet which is in/will be in the book in a jupyter notebook. At the moment, I'm thinking it's best to put this in at the end because I want to get the main meat of the book migrated.

There is a lot of work to do in rewriting this section, but I think it should be done towards the end as it is mostly about signposting for later sections.

Before I merge this PR though, I will finish fixing the citations (GO and summary section).