Add search parameter to show all concerts

When loading the page with the |?showAllConcerts| paramter in the URL,
all concerts (including future ones) will be shown in the "Previous
concerts" list.

Change-Id: Id42e085beb24b3d068ee0a503395d4bdf34ef168
diff --git a/js/script.js b/js/script.js
index 522f0f0..90ae29b 100644
--- a/js/script.js
+++ b/js/script.js
@@ -5,6 +5,7 @@
 
 var interval = null;
 var isBookletShown = false;
+var showAllConcerts = false;
 
 function showSection(section) {
   document.querySelectorAll('section').forEach(el => {
@@ -96,7 +97,7 @@
 
   var existsPreviousConcert = false;
   booklets.forEach(booklet => {
-    if (booklet.ends * 1000 <= now) {
+    if (showAllConcerts || booklet.ends * 1000 <= now) {
       existsPreviousConcert = true;
 
       var el = document.createElement('div');
@@ -160,6 +161,10 @@
             .setAttribute('hidden', '');
       });
 
+  var searchParams = new URLSearchParams(location.search);
+  if (searchParams.has('showAllConcerts'))
+    showAllConcerts = true;
+
   if ('serviceWorker' in navigator) {
     navigator.serviceWorker.register('/sw.js')
         .then(reg => {
diff --git a/sw.js b/sw.js
index 011d5f5..95db678 100644
--- a/sw.js
+++ b/sw.js
@@ -1,4 +1,4 @@
-// Version: 1.0.8
+// Version: 1.0.9
 var CACHE_NAME = 'all-v1';
 var urlsToCache = [
   '/',