Memory Monitor: Change else ifs to ifs (#516)

* library: Add Memory Monitor entry

* Update main.json

* Update main.blp

* Memory Monitor: Suggestions

* Memory Monitor: Change else ifs to ifs

src/Library/demos/Memory Monitor/main.js

@@ -13,10 +13,12 @@ memory_monitor.connect("low-memory-warning", (monitor, level) => {
     // Processes should free up unneeded resources
     console.log("Warning Level: Low");
     drop_caches();
-  } else if (level >= Gio.MemoryMonitorWarningLevel.MEDIUM) {
+  }
+  if (level >= Gio.MemoryMonitorWarningLevel.MEDIUM) {
     // Processes should try harder to free up unneeded resources
     console.log("Warning Level: Medium");
-  } else if (level >= Gio.MemoryMonitorWarningLevel.CRITICAL) {
+  }
+  if (level >= Gio.MemoryMonitorWarningLevel.CRITICAL) {
     // system will start terminating processes to reclaim memory
     console.log("Warning Level: Critical");
   }