feat(dashboard): move generic.scss to themes file

dashboard/index.html

@@ -6,7 +6,6 @@
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
     <title>PluralKit | home</title>
     <!-- extra data -->
-    <link rel="stylesheet" href="/styles/generic.scss" />
     <link rel="stylesheet" href="/styles/themes.scss" />
     <script defer data-domain="dash.pluralkit.me" src="https://plausible.pluralkit.me/js/plausible.js"></script>
   </head>

dashboard/styles/themes.scss

@@ -1,6 +1,7 @@
 $primary: #da9317;
 $primary-alt: #da9317;
 @import "../node_modules/bootstrap/scss/bootstrap.scss";
+@import "generic.scss";
 
 // dark mode. dark.scss extends nightshade
 @import "bootstrap-nightshade.scss";