[docs] /system/getting-started/advanced/ does not exist

[MonstraG]

Duplicates

• I have searched the existing issues

https://mui.com/system/getting-started/overview/
Links to
https://mui.com/system/getting-started/advanced/
in the last line:

which doesn't exist

[ZeeshanTamboli]

Thanks for reporting. It's after changes in #33503. The fix should be simple:

--- a/docs/data/system/getting-started/overview/overview.md
+++ b/docs/data/system/getting-started/overview/overview.md
@@ -27,4 +27,4 @@ Learn more on [the `sx` prop page](/system/getting-started/the-sx-prop/).
 [MUI Base](/base/getting-started/overview/) is a library of "unstyled" React components, while MUI System is a set of
utilities for quickly applying styles to those components (as well as other MUI component libraries like Material UI and Joy UI).

 MUI Base is a standalone component library, whereas the System is _supplemental_ in that it's designed to be paired with Base and other MUI components, as well as third-party components.
-See [Advanced](/system/getting-started/advanced/) for details on how to use MUI System with non-MUI components.
+See the [Custom components page](/system/getting-started/custom-components/) for details on how to use MUI System with non-MUI components.

Would you like to create a PR for it?

[MonstraG]

done^