Update UI design across multiple pages and components

Several changes have been made to improve the user interface and enhance the user experience. This includes redesigning Auth buttons, modifying website layouts and routing, tweaking heading and text sizes for clarity, and revamping the marketing, documentation, and pricing pages. These changes collectively contribute to a cleaner, more concise and navigable interface.

apps/web/app/(marketing)/layout.tsx

@@ -1,5 +1,4 @@
 import { getSupabaseServerComponentClient } from '@kit/supabase/server-component-client';
-import { Separator } from '@kit/ui/separator';
 
 import { SiteFooter } from '~/(marketing)/_components/site-footer';
 import { SiteHeader } from '~/(marketing)/_components/site-header';
@@ -9,13 +8,11 @@ async function SiteLayout(props: React.PropsWithChildren) {
   const user = await getUser();
 
   return (
-    <div className={'flex flex-col space-y-6 xl:space-y-10 2xl:space-y-12'}>
+    <div className={'flex flex-col'}>
       <SiteHeader user={user} />
 
       {props.children}
 
-      <Separator />
-
       <SiteFooter />
     </div>
   );