chapter 1 exercise note about type signatures for functions with multiple arguments

errata

@@ -1,3 +1,7 @@
+# Chapter 1
+
+- Exercise 1.4: Until this point, demonstrated functions have a single argument and a single return value. The reader won't see until the start of Chapter 4 (pg 36) that type definitions have a `->` between all types, rather than the arrow separating the arguments from the return values.
+
 # Chapter 3
 
 - page 23 (missing text in square brackets): "Here b is an expression of type Bool called the condition[, c] is called the consequent[, and a] is called the alternative."