[docs] Add warning for luxon macro tokens (mui#8245)

docs/data/date-pickers/adapters-locale/adapters-locale.md

@@ -65,6 +65,16 @@ import { AdapterLuxon } from '@mui/x-date-pickers/AdapterLuxon';
 
 {{"demo": "LocalizationLuxon.js"}}
 
+:::warning
+The Date and Time Pickers are not working well with Luxon macro-token (`D`, `DD`, `T`, `TT`, ...),
+because of [how they are expanded](https://github.com/mui/mui-x/issues/7615).
+
+If your application is using only a single locale, the easiest solution is to manually provide a format that does not contain any macro-token
+(e.g. `M/d/yyyy` instead of `D` for the english locale).
+
+As soon as a solution is found the built-in support will be improved.
+:::
+
 ### With `moment`
 
 For `moment`, import the locale and then pass its name to `LocalizationProvider`:

docs/data/date-pickers/overview/overview.md

@@ -42,6 +42,16 @@ The Date and Time Pickers currently support the following date libraries:
 - [Luxon](https://moment.github.io/luxon/#/)
 - [Moment.js](https://momentjs.com/)
 
+:::warning
+The Date and Time Pickers are not working well with Luxon macro-token (`D`, `DD`, `T`, `TT`, ...),
+because of [how they are expanded](https://github.com/mui/mui-x/issues/7615).
+
+If your application is using only a single locale, the easiest solution is to manually [provide a format](/x/react-date-pickers/adapters-locale/#custom-formats) that does not contain any macro-token
+(e.g. `M/d/yyyy` instead of `D` for the english locale).
+
+As soon as a solution is found the built-in support will be improved.
+:::
+
 :::info
 If you are using a non-Gregorian calendar (such as Jalali or Hijri), please refer to the [Support for other calendar systems](/x/react-date-pickers/calendar-systems/) page.
 :::