nut13 specify keyset ID integer size: 32 bits

13.md

@@ -42,7 +42,7 @@ The wallet starts with `counter_k := 0` upon encountering a new keyset and incre
 
 #### Keyset ID
 
-The integer representation `keyset_id_int` of a keyset is calculated from its [hexadecimal ID][02] which has a length of 8 bytes or 16 hex characters. First, we convert the hex string to a big-endian sequence of bytes. This value is then modulo reduced by `2^31 - 1` to arrive at an integer that is a unique identifier `keyset_id_int`.
+The 32 bit integer representation `keyset_id_int` of a keyset is calculated from its [hexadecimal ID][02] which has a length of 8 bytes or 16 hex characters. First, we convert the hex string to a big-endian sequence of bytes. This value is then modulo reduced by `2^31 - 1` to arrive at an integer that is a unique identifier `keyset_id_int`.
 
 Example in Python:
 ```python