feat: add vditor locally

public/vditor/ts/preview/index.d.ts

@@ -0,0 +1,10 @@
+/// <reference types="./types" />
+export declare class Preview {
+    element: HTMLElement;
+    previewElement: HTMLElement;
+    private mdTimeoutId;
+    constructor(vditor: IVditor);
+    render(vditor: IVditor, value?: string): void;
+    private afterRender;
+    private copyToX;
+}