[docs] Add links to mui-treasury (#19334)

Author: siriwatknp

docs/src/pages/components/cards/cards.md

@@ -48,3 +48,8 @@ Supplemental actions within the card are explicitly called out using icons, text
 Here's an example of a media control card.
 
 {{"demo": "pages/components/cards/MediaControlCard.js", "bg": true}}
+
+## Customization
+
+👑 If you are looking for inspiration, you can check [MUI Treasury's customization examples](https://mui-treasury.com/components/card).
+

docs/src/pages/components/lists/lists.md

@@ -96,3 +96,7 @@ Virtualization helps with performance issues.
 
  The use of [react-window](https://github.com/bvaughn/react-window) when possible is encouraged.
 If this library doesn't cover your use case, you should consider using [react-virtualized](https://github.com/bvaughn/react-virtualized), then alternatives like [react-virtuoso](https://github.com/petyosi/react-virtuoso).
+
+## Customization
+
+👑 If you are looking for inspiration, you can check [MUI Treasury's customization examples](https://mui-treasury.com/components/menu-list).

docs/src/pages/components/text-fields/text-fields.md

@@ -120,6 +120,8 @@ Below is an example using the [`InputBase`](/api/input-base/) component, inspire
 
 {{"demo": "pages/components/text-fields/CustomizedInputBase.js", "bg": true}}
 
+👑 If you are looking for inspiration, you can check [MUI Treasury's customization examples](https://mui-treasury.com/components/text-field).
+
 ## Limitations
 
 ### Shrink

docs/src/pages/discover-more/related-projects/related-projects.md

@@ -25,6 +25,10 @@ You didn't find the design assets your team is looking for? Let us know!
 
 This is a collection of third-party projects that extend Material-UI.
 
+### Layout
+
+- [@mui-treasury/layout](https://mui-treasury.com/layout): Components to handle the overall layout of a page. You can find a couple of examples, e.g. [a reactjs.org clone](https://mui-treasury.com/layout/clones/reactjs).
+
 ### Tables
 
 - [material-table](https://github.com/mbrn/material-table): A simple and powerful Datatable for React based on Material-UI Table with some additional features.