Added "https://" prefix to all URLs so they are clickable in VS Code

examples/JsonUdpBeacon/JsonUdpBeacon.ino

@@ -1,4 +1,4 @@
-// ArduinoJson - arduinojson.org
+// ArduinoJson - https://arduinojson.org
 // Copyright Benoit Blanchon 2014-2021
 // MIT License
 //
@@ -46,7 +46,7 @@ void setup() {
 
 void loop() {
   // Allocate a temporary JsonDocument
-  // Use arduinojson.org/v6/assistant to compute the capacity.
+  // Use https://arduinojson.org/v6/assistant to compute the capacity.
   StaticJsonDocument<500> doc;
 
   // Create the "analog" array