[Typescript] Add Breadcrumb.d.ts file

Add typescript type definition for Breadcrumbs, so that
it can be type checked.

jsx/Breadcrumbs.d.ts

@@ -0,0 +1,26 @@
+import React from 'react';
+
+type breadcrumb = {
+    text: string
+    onClick?: (e: React.MouseEvent) => void
+}
+
+type breadcrumbProps = {
+    baseURL: string,
+    breadcrumbs: breadcrumb[],
+};
+
+
+class Breadcrumbs {
+    props: breadcrumbProps
+    state: {displayCount: number}
+    context: object
+    refs: {[key: string]: ReactInstance}
+
+    constructor(props: breadcrumbProps)
+    render(): ReactNode
+    setState(newprops: object): void
+    forceUpdate(): void
+}
+
+export default Breadcrumbs;