style: format code with Prettier and remove unused code

Change-Id: I382f39d142cfa29f192447b0d2c6d48e113327b4
diff --git a/pageevent.js b/pageevent.js
index ad7ac40..587862c 100644
--- a/pageevent.js
+++ b/pageevent.js
@@ -1,14 +1,14 @@
-chrome.runtime.onInstalled.addListener(function() {
-  chrome.declarativeContent.onPageChanged.removeRules(undefined, function() {
-     chrome.declarativeContent.onPageChanged.addRules([
-       {
-         conditions: [
-           new chrome.declarativeContent.PageStateMatcher({
-             pageUrl: { schemes: ['http', 'https'] },
-           })
-         ],
-        actions: [ new chrome.declarativeContent.ShowPageAction() ]
-      }
+chrome.runtime.onInstalled.addListener(function () {
+  chrome.declarativeContent.onPageChanged.removeRules(undefined, function () {
+    chrome.declarativeContent.onPageChanged.addRules([
+      {
+        conditions: [
+          new chrome.declarativeContent.PageStateMatcher({
+            pageUrl: { schemes: ["http", "https"] },
+          }),
+        ],
+        actions: [new chrome.declarativeContent.ShowPageAction()],
+      },
     ]);
   });
 });