clarify pruned nodes support

Author: adrienlacombe

README.md

@@ -47,7 +47,7 @@ Ledger SatStack is a standalone Go application, that acts as a bridge between th
 - Bitcoin Nano app **`2+`**
 - Bitcoin Core **`0.22.0+`**.
 - Ledger Live (desktop) **`2.44.0+`**.
-- `txindex=1` in `bitcoin.conf` is not mandatory, but recommended.
+- `txindex=1` in `bitcoin.conf` is not mandatory, but recommended. Pruned nodes are not currently supported.
 - Wallet should **NOT** be disabled (attn. Raspiblitz users).
 
 ### Usage