web: start implementing translation in JS

web/src/django.d.ts

@@ -0,0 +1,10 @@
+declare module 'django' {
+    export = django;
+}
+declare namespace django {
+    function gettext(name: string): string;
+    function ngettext(singular: string, plural: string, count: number): string;
+    function gettext_noop(msgid: string): string;
+    function pgettext(context: string, msgid: string): string;
+    function interpolate(fmt: string, obj: any, named: boolean): string;
+}