Update deploy-a-hexo-site.mdx, remove unnecessary npm install steps (#18931)

Author: ousugo

src/content/docs/pages/framework-guides/deploy-a-hexo-site.mdx

@@ -34,7 +34,6 @@ With Hexo CLI installed, create a new project by running the `hexo init` command
 ```sh
 hexo init my-hexo-site
 cd my-hexo-site
-npm install
 ```
 
 Hexo sites use themes to customize the appearance of statically built HTML sites. Hexo has a default theme automatically installed, which you can find on [Hexo's Themes page](https://hexo.io/themes/).