I write my books (5 published so far through Elsevier and others) in Markdown. It seems the OP uses markdown too. I wondered how he did footnotes in plain text

I write my books (5 published so far through Elsevier and others) in Markdown. It seems the OP uses markdown too. I wondered how he did footnotes in plain text, he just uses a markdown-style syntax. It is an excellent approach with benefits over LaTeX. It has better separation of appearance and content, the content tends to have less visual clutter, and there are pleasant tools for distraction free writing, which I personally like. I wrote my thesis and academic papers in LaTeX, so I have used it a lot. The downside (for both LaTeX and markdown) is dealing with proofing at a publisher. This is minor the first time, but getting a corrected manuscript back from the editor when you need to work on a second edition can prove very cumbersome.