v3.0.0

修复bug，新增特性。

What's Changed

• bug:搜索 by @tangly1024 in #140
• Preview by @tangly1024 in #141
• hexo: 文章页默认背景图 by @tangly1024 in #142
• Feature og url image, path env fix for vercel deploy by @txs in #146
• Better SEO for Facebook Open Graph by @txs in #152
• Feature last update time by @tangly1024 in #155
• bug-滚动到评论区 by @tangly1024 in #156
• Add Facebook Customer Chat for the blogging system by @txs in #153
• Feature facebook messenger customer chat plugin no ssr by @txs in #154

Full Changelog: v2.9.1...v3.0.0