docs: correctly identify script type

fixes a typo

Author: niftynei

doc/descriptors.md

@@ -191,7 +191,7 @@ steps, or for dumping wallet descriptors including private key material.
 In order to easily represent the sets of scripts currently supported by
 existing Bitcoin Core wallets, a convenience function `combo` is
 provided, which takes as input a public key, and describes a set of P2PK,
-P2PKH, P2WPKH, and P2SH-P2WPH scripts for that key. In case the key is
+P2PKH, P2WPKH, and P2SH-P2WPKH scripts for that key. In case the key is
 uncompressed, the set only includes P2PK and P2PKH scripts.
 
 ### Checksums