docs: update wallet description how-to

docs/how-to-guides/how-to-use-chainhooks-with-bitcoin.md

@@ -152,6 +152,31 @@ Get any transaction, including a `p2wsh` output paying a given recipient:
 
 `p2wsh`  (Pay-to-Witness-Script-Hash) is a Bitcoin transaction output script type used in Segregated Witness (SegWit) that enables users to send funds to a hashed script, allowing for more complex transaction conditions and greater scalability by separating the script from the transaction data.
 
+**Wallet Descriptors** provide a compact and semi-standardized method for describing how scripts and addresses within a wallet are generated. Chainhooks users that want to track addresses derived from an extended pubkey or a multisig-wallet for example, can now rely on this feature instead of defining one predicate per address.
+For example if we wanted to track the first 3 addressed generated by the following descriptor:
+```
+wpkh(tprv8ZgxMBicQKsPePxn6j3TjvB2MBzQkuhGgc6oRh2WZancZQgxktcnjZJ44XdsRiw3jNkbVTK9JW6KFHvnRKgAMtSyuBevMJprSkZ4PTfmTgV/84'/1'/0'/0/*)
+```
+which reads: describe a P2WPKH output with the specified extended public key, and produces these BIP84 addresses:
+
+```
+bcrt1qzy2rdyvu8c57qd8exyyp0mw7dk5drsu9ewzdsu
+bcrt1qsfsjnagr29m8h3a3vdand2s85cg4cefkcwk2fy
+bcrt1qauewfytqe5mtr0xwp786r6fl39kmum2lr65kmj
+```
+The following predicate should be defined:
+```json
+{
+    "if_this": {
+        "scope": "outputs",
+        "descriptor": {
+            "expression": "wpkh(tprv8ZgxMBicQKsPePxn6j3TjvB2MBzQkuhGgc6oRh2WZancZQgxktcnjZJ44XdsRiw3jNkbVTK9JW6KFHvnRKgAMtSyuBevMJprSkZ4PTfmTgV/84'/1'/0'/0/*)",
+            "range": [0,3]
+        }
+    }
+}
+```
+
 Get any Bitcoin transaction, including a Block commitment. Broadcasted payloads include _Proof of Transfer_ reward information:
 
 ```json