doc: Update example to be valid codex32 string

I guess this was to honor Aditya, but it was also a wrong example.

Signed-off-by: Peter Neuroth <pet.v.ne@gmail.com>

doc/lightning-hsmtool.8.md

@@ -74,7 +74,7 @@ This produces the same results as lightning-commando-rune(7) on a fresh node.
 You will still need to create a rune once the node starts, if you want commando to work (as it is only activated once it has generated one).
 
 **getcodexsecret** *hsm\_secret\_path* *id*
-  Print out the BIP-93 formatted HSM secret, for use with `--recover`.  The `id` is any 4 character string you can use to identify this secret (e.g. `adi0`): it cannot contain `i`, `o`, or `b`, but can contain digits except `1`.
+  Print out the BIP-93 formatted HSM secret, for use with `--recover`.  The `id` is any 4 character string you can use to identify this secret (e.g. `ad00`): it cannot contain `i`, `o`, or `b`, but can contain digits except `1`.
 
 **getemergencyrecover** *emergency.recover\_path*
   Print out the bech32 encoded emergency.recover file.