docs: update homepage footer

Author: Mister-Hope

docs/readme.md

@@ -12,6 +12,8 @@ actions:
   - text: 知识星球
     link: /about-the-author/zhishixingqiu-two-years.md
     type: default
+footer: |-
+  <a href="https://beian.miit.gov.cn/" target="_blank">鄂ICP备2020015769号-1</a> | 主题: <a href="https://vuepress-theme-hope.github.io/v2/" target="_blank">VuePress Theme Hope</a>
 ---
 
 ## 必看专栏