📝 mention that this package isn't stable yet

Author: jorenham

README.md

@@ -3,6 +3,12 @@
 
 ---
 
+> [!WARNING]
+> This package is in early development and is not yet stable. It is intended as a typing toolkit
+> for working the [Python array API standard](https://data-apis.org/array-api/latest/), but it
+> may change significantly in the future.
+
+
 ## Installation
 
 ```bash
@@ -49,4 +55,4 @@ pip install -e .  # editable mode
 >>> func(np.array([1, 2, 3]))
 array([1, 2, 3])
 
-```
+```