Docs nits

src/timer.h

@@ -3,14 +3,15 @@
 struct mg_timer {
   unsigned long period_ms;  // Timer period in milliseconds
   unsigned flags;           // Possible flags values below
-#define MG_TIMER_REPEAT 1   // Call function periodically, otherwise run once
-#define MG_TIMER_RUN_NOW 2  // Call immediately when timer is set
   void (*fn)(void *);       // Function to call
   void *arg;                // Function argument
   unsigned long expire;     // Expiration timestamp in milliseconds
   struct mg_timer *next;    // Linkage in g_timers list
 };
 
+#define MG_TIMER_REPEAT 1   // Call function periodically, otherwise run once
+#define MG_TIMER_RUN_NOW 2  // Call immediately when timer is set
+
 extern struct mg_timer *g_timers;  // Global list of timers
 
 void mg_timer_init(struct mg_timer *, unsigned long ms, unsigned,