Multisite support

I tried installing this on my multisite network. When I network enable the plugin, the plugin settings do not show up in the network admin panel.

I was able to enable it on one of my individual network sites, but had a bit of difficulty accessing the settings. When I first tried right after I installed it on my network, it gave me a permissions error. Then I tried again and I was able to access the settings page (from the admin panel of the individual site where I enabled the plugin).

https://ww.wp.xz.cn/plugins/smooth-scroll-up/