Allow testing the celebration by tapping the tagline six times

On mobile phones, it is a bit of a challenge to press the "2" key
followed by the "0" key to test out the 20th anniversary celebrations.
Implement a multi-tap listener for that, specifically on the "tagline"
so as not to spoil the surprise by mistake.

I considered requiring 20 taps because it is the 20th anniversary, but I
also want to test efficiently, so there.

Signed-off-by: Johannes Schindelin <[email protected]>

Author: dscho

assets/js/application.js

@@ -111,6 +111,18 @@ var GitTurns20 = {
     const today = new Date();
     if (today.getFullYear() === 2025 && today.getMonth() === 3 && today.getDate() === 7) {
       this.celebrate();
+    } else {
+      let start = 0
+      let count = 0
+      $("#tagline").click(e => {
+        if (count === 0 || e.timeStamp > start + count * 1000) {
+          start = e.timeStamp;
+          count = 1;
+        } else if (++count === 6) {
+          this.celebrate();
+          count = 0;
+        }
+      })
     }
   },