Remove more bits surrounding hmr

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

src/vector/index.ts

@@ -22,14 +22,6 @@ import "./modernizr";
 // in webpack.config.js
 require("katex/dist/katex.css");
 
-/**
- * This require is necessary only for purposes of CSS hot-reload, as otherwise
- * webpack has some incredible 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");
 require("./localstorage-fix");
 
 async function settled(...promises: Array<Promise<any>>): Promise<void> {