use an integer example for the second to make it more obvious that the cache stores anything, not just strings

README

@@ -22,10 +22,10 @@ c := cache.New(5*time.Minute, 30*time.Second)
 // Set the value of the key "foo" to "bar", with the default expiration time
 c.Set("foo", "bar", 0)
 
-// Set the value of the key "baz" to "yes", with no expiration time
+// Set the value of the key "baz" to 42, with no expiration time
 // (the item won't be removed until it is re-set, or removed using
 // c.Delete("baz")
-c.Set("baz", "yes", -1)
+c.Set("baz", 42, -1)
 
 // Get the string associated with the key "foo" from the cache
 foo, found := c.Get("foo")