Add try/catch to JS sample

Author: anthonychu

articles/azure-functions/durable/durable-functions-overview.md

@@ -75,10 +75,14 @@ You can use the `context` parameter to invoke other functions by name, pass para
 const df = require("durable-functions");
 
 module.exports = df.orchestrator(function*(context) {
-    const x = yield context.df.callActivity("F1");
-    const y = yield context.df.callActivity("F2", x);
-    const z = yield context.df.callActivity("F3", y);
-    return    yield context.df.callActivity("F4", z);
+    try {
+        const x = yield context.df.callActivity("F1");
+        const y = yield context.df.callActivity("F2", x);
+        const z = yield context.df.callActivity("F3", y);
+        return    yield context.df.callActivity("F4", z);
+    } catch (error) {
+        // Error handling or compensation goes here.
+    }
 });
 ```