export embedded katex as window global

src/components.js

@@ -1,5 +1,6 @@
 /* Static styles and other modules */
 import './styles/styles';
+import katex from 'katex';
 
 /* Components */
 import { Abstract }         from './components/d-abstract';
@@ -42,3 +43,4 @@ function defineComponents() {
 }
 
 defineComponents();
+window.katex = katex;