feature:

新增StickyBar组件；
标签页、分类页、搜索页重排；

components/CategoryList.js

@@ -0,0 +1,26 @@
+import Link from 'next/link'
+import React from 'react'
+
+const CategoryList = ({ currentCategory, categories }) => {
+  return <ul className='flex py-1 space-x-3'>
+    <li className='w-10 py-2 dark:text-gray-200'>分类:</li>
+    {Object.keys(categories).map(category => {
+      const selected = category === currentCategory
+      return (
+      <Link key={category} href={`/category/${category}`}>
+          <li
+            className={`cursor-pointer border hover:bg-gray-300 rounded-xl duration-200 mr-1 my-1 px-2 py-1 font-medium font-light text-sm whitespace-nowrap
+                 dark:text-gray-300 dark:hover:bg-gray-800 ${selected ? 'text-white bg-black dark:hover:bg-gray-900 dark:bg-black dark:border-gray-800' : 'bg-gray-100 text-gray-600 dark:bg-gray-600 dark:border-gray-600'
+            }`}
+          >
+            <a>
+              <i className='fa fa-folder-open-o mr-1'/>
+              {`${category} `}
+            </a>
+          </li>
+        </Link>)
+    })}
+  </ul>
+}
+
+export default CategoryList