update readme

lijin-THU · lijin-THU · commit 390fbd6cf273 · 2017-04-11T17:07:10.000+08:00
diff --git a/index.ipynb b/index.ipynb
@@ -268,7 +268,7 @@
    "source": [
     "觉得有用打赏一下？\n",
     "\n",
-    "<img src=\"payment.jpg\", width=20%/>"
+    "![](payment.jpg)"
    ]
   }
  ],
