document.body is accessed very early in scripts loading, in
https://github.com/microsoft/vscode/blob/c6e3a94892eaccbce9995ee02a06febec5492fec/src/vs/editor/contrib/suggest/suggestRangeHighlighter.ts#L106
if we leave body after head, for some reason document.body is null here
and loading fail, which leaves an editor where things like Ctrl+Space
does not trigger completions

Moving body before head is just a workaround, but that was code was
removed in
https://github.com/microsoft/vscode/commit/f913854bd66362a1350ea43c305ad92c151796bf
hopefully when we update to monaco > 0.20.0 that won't be needed again.