Tweak spacing

_includes/frontpage_racket_example1.md

@@ -1,7 +1,8 @@
 ```racket
 (actor
- (react (field [balance 0])
-        (assert (account (balance)))
-        (on (message (deposit $amount))
-            (balance (+ (balance) amount)))))
+ (react
+  (field [balance 0])
+  (assert (account (balance)))
+  (on (message (deposit $amount))
+      (balance (+ (balance) amount)))))
 ```

_includes/frontpage_racket_example2.md

@@ -1,6 +1,7 @@
 ```racket
 (actor
- (react (on (asserted (account $balance))
-            (printf "Balance: ~a\n"
-                    balance))))
+ (react
+  (on (asserted (account $balance))
+      (printf "Balance: ~a\n"
+              balance))))
 ```