Make CSS Hot-reload work in a hacky way

src/vector/index.ts

@@ -25,6 +25,14 @@ require('gfm.css/gfm.css');
 require('highlight.js/styles/github.css');
 require('katex/dist/katex.css');
 
+/**
+ * This require is necessary only for purposes of CSS hot reload, as otherwise
+ * webpack has some incredibly problems figuring out which css files should be
+ * hot reloaded, even with proper hints for the loader.
+ *
+ * On production build it's going to be an empty module, so don't worry about that.
+ */
+require('./devcss');
 // These are things that can run before the skin loads - be careful not to reference the react-sdk though.
 import { parseQsFromFragment } from "./url_utils";
 import './modernizr';