Add DefaultPage doc

types/query/pagination.go

@@ -11,6 +11,8 @@ import (
 	"github.com/cosmos/cosmos-sdk/store/types"
 )
 
+// DefaultPage is the default `page` number for queries.
+// If the `page` number is not supplied, `DefaultPage` will be used.
 const DefaultPage = 1
 
 // DefaultLimit is the default `limit` for queries