D syntax highlighting is set to use the wrong extension.

Syntax highlighting for the D programming language is currently not functional. Looking at the static/feature/file-content/source-view/source-view.js file, support is there but it's set to use the .a file extension. It should be using .d and .di as the file extensions. Uploading a file with the .a extension is highlighted as D should be.

Very basic example file:

import std.stdio;

void main()