Clarify what the number of inputs field is actually

Author: achow101

bip-0174.mediawiki

@@ -185,9 +185,9 @@ Value:
 </pre>
 |-
 | <tt>0x04</tt>
-| Number of inputs
+| Number of inputs provided in the PSBT
 | None. The key must only contain the 1 byte type.
-| A compact size unsigned integer representing the number of inputs that this transaction has
+| A compact size unsigned integer representing the number of inputs that this PSBT has
 | Key: 
 <pre>
 {0x04}
@@ -265,7 +265,7 @@ Value:
 | <tt>0x04</tt>
 | Input index
 | None. The key must only contain the 1 byte type.
-| A compact size unsigned integer representing the index of this input. This field
+| A compact size unsigned integer representing the 0-based index of this input. This field
 is optional to allow for completed inputs to be skipped without needing a separator byte.
 If one input has this type, then all inputs must have it.
 | Key: