first version for user js tasks

lib/exampletask/index.js

@@ -0,0 +1,12 @@
+(function(){
+    let isActive=false;
+    window.esp32nmea2k.registerListener((id,data)=>{
+        if (id === 0){
+            //data is capabilities
+            if (data.testboard) isActive=true;
+        }
+        if (isActive){
+            console.log("exampletask listener",id,data);
+        }
+    })
+})();