While reading the build docs, I found some opportunities for textual improvements (Force of habit, I used to work as a technical writer...)
Added a few missing words, should be uncontroversial.
Changed/added some punctuation, for better flow and readability.
Fixed one Markdown issue, where two list item headings rendered without a line break. (See image) This one needs to be verified after a build, I don't have a proper build environment yet.
<img width="403" alt="layout_issue" src="https://user-images.githubusercontent.com/453092/47555613-893b4d00-d90c-11e8-8a31-943846059ae7.png">