Switch to react

Under the hood, preact is used to reduce dependency size. We still don't
have a build stage, so htm is used instead of JSX.

lib/index.js

@@ -0,0 +1,5 @@
+export * from "/node_modules/preact/dist/preact.module.js";
+
+import { h } from "/node_modules/preact/dist/preact.module.js";
+import htm from "/node_modules/htm/dist/htm.module.js";
+export const html = htm.bind(h);