Fix getting-started.md Run function, it assigns this new context to a…

… variable shared between connections in to accept loop. Thus creating a growing chain of contexts. so every calculate fibonacci request, all spans in a trace.

website_docs/getting-started.md

@@ -184,16 +184,15 @@ Start by instrumenting the `Run` method.
 // Run starts polling users for Fibonacci number requests and writes results.
 func (a *App) Run(ctx context.Context) error {
 	for {
-		var span trace.Span
-		ctx, span = otel.Tracer(name).Start(ctx, "Run")
+		newCtx, span := otel.Tracer(name).Start(ctx, "Run")
 
-		n, err := a.Poll(ctx)
+		n, err := a.Poll(newCtx)
 		if err != nil {
 			span.End()
 			return err
 		}
 
-		a.Write(ctx, n)
+		a.Write(newCtx, n)
 		span.End()
 	}
 }