bring local dev flarum-webpack-config to core for easier development

js/webpack-flarum-shims.d.ts

@@ -0,0 +1,19 @@
+import * as Mithril from 'mithril';
+import Stream from 'mithril/stream';
+
+import * as _dayjs from 'dayjs';
+import classNames from 'classnames';
+
+interface m extends Mithril.Static {
+    prop: Stream.Static;
+}
+
+declare global {
+    const m: m;
+    const dayjs: typeof _dayjs;
+    const classNames: classNames;
+}
+
+export as namespace Mithril;
+
+export {};