Document the dst param

Author: FrancescAlted

blosc2/utils.py

@@ -100,6 +100,11 @@ def decompress(src, dst=None, as_bytearray=False):
         The data to be decompressed.  Must be a bytes-like object
         that supports the Python Buffer Protocol, like bytes, bytearray,
         memoryview, or numpy.ndarray.
+    dst : NumPy object
+        The destination NumPy object to fill.  The user must make sure
+        that it has enough capacity for hosting the decompressed data.
+        Default is None, meaning that a new `bytes` or `bytearray` object
+        is created, filled and returned.
     as_bytearray : bool (optional)
         If this flag is True then the return type will be a bytearray object
         instead of a bytesobject.