Update getting-started-local-single-node.md (apache#3425)

Wget link for macos

website2/docs/getting-started-local-single-node.md

@@ -57,6 +57,10 @@ To install Heron binaries directly, using installation scripts, go to Heron's [r
 and see a full listing of Heron releases for each available platform. The installation script for macOS (`darwin`), for example, is named
 `heron-install-{{% heronVersion %}}-darwin.sh`.
 
+```bash
+$ wget https://github.com/apache/incubator-heron/releases/download/{{% heronVersion %}}/heron-install-{{% heronVersion %}}-darwin.sh
+```
+
 Download the for your platform either from the releases page or using [`wget`](https://www.gnu.org/software/wget/). Here's a `wget` example for Ubuntu:
 
 ```bash
@@ -282,4 +286,4 @@ In case of any issues, please refer to [Quick Start Troubleshooting](getting-sta
 * [Deploy topologies](deployment-overview) in clustered, scheduler-driven
   environments (such as on [Aurora](schedulers-aurora-cluster)
   and [locally](schedulers-local))
-* [Develop topologies](heron-architecture) for Heron
+* [Develop topologies](heron-architecture) for Heron