📝 update link

bnd2/react/src/pages/welcome.js

@@ -274,16 +274,16 @@ export default class Welcome extends React.Component {
               </Typography>
               <Typography variant="h5" className={classes.link}
                           component="h2" onClick={openURL.bind(this,
-                'http://hacpai.com')}>
-                黑客派社区
+                'https://github.com/b3log/30-seconds-zh_CN')}>
+                每天 30 秒带你学前端
               </Typography>
             </CardContent>
             <CardActions>
               <Button size="small" className={classes.ftOriginal}
                       onClick={openURL.bind(this,
-                        'https://hacpai.com/tag/bnd')}>
+                        'https://hacpai.com/domain/frontend')}>
                 ⚡️
-                浏览 BND 相关讨论
+                浏览前端相关讨论
               </Button>
             </CardActions>
           </Card>