docs: DX and performance improvements in API reference (#9430)

- Improve scroll behavior between active sections
- Improve lag when clicking on a sidebar item
- Refactor internal working of the `SidebarProvider` to find active items faster.
- Use Next.js's `useRouter` hook for changing the hash (since they added the option to disable scroll)
- Change `isBrowser` from a hook to a provider since it's widely used across applications.
- Other general improvements and fixes.

Closes DOCS-952

www/packages/docs-ui/src/components/RootProviders/index.tsx

@@ -0,0 +1,25 @@
+"use client"
+
+import React from "react"
+import {
+  BrowserProvider,
+  ColorModeProvider,
+  MobileProvider,
+  ModalProvider,
+} from "../../providers"
+
+type RootProvidersProps = {
+  children: React.ReactNode
+}
+
+export const RootProviders = ({ children }: RootProvidersProps) => {
+  return (
+    <BrowserProvider>
+      <MobileProvider>
+        <ColorModeProvider>
+          <ModalProvider>{children}</ModalProvider>
+        </ColorModeProvider>
+      </MobileProvider>
+    </BrowserProvider>
+  )
+}