Update README.md (#2043)

Co-authored-by: Laurent Raufaste <[email protected]>

README.md

@@ -2,10 +2,11 @@
 
 Keep your application settings in sync.
 
-## Table of content
+## Table of contents
 
 - [Mackup](#mackup)
-  - [Table of content](#table-of-content)
+  - [Table of contents](#table-of-contents)
+  - [WARNING](#warning)
   - [Quickstart](#quickstart)
   - [Usage](#usage)
   - [What does it do](#what-does-it-do)
@@ -23,6 +24,14 @@ Keep your application settings in sync.
   - [What's up with the weird name](#whats-up-with-the-weird-name)
   - [Where can I find more information](#where-can-i-find-more-information)
 
+## WARNING
+
+⚠️ Mackup does not work correctly in Macos Sonoma, since it does not support
+symlinked files for preferences. Running this code will destroy all user
+preferences without a means for recovery. For more information, see issues
+[#1924](https://github.com/lra/mackup/issues/1924) and
+[2035](https://github.com/lra/mackup/issues/2035).
+
 ## Quickstart
 
 If you have [Dropbox](https://www.dropbox.com) installed and want to use it to