Removed reference to set up article (SharePoint#2836)

If there were details on installing a developer certificate in the set up article, they are not there now. At any rate, in my test, no more details were needed.

Author: tomresing

docs/spfx/web-parts/get-started/build-a-hello-world-web-part.md

@@ -380,7 +380,7 @@ SharePoint Workbench is also hosted in SharePoint to preview and test your local
 1. Go to the following URL: `https://your-sharepoint-tenant.sharepoint.com/_layouts/workbench.aspx`
 
   > [!NOTE]
-  > If you do not have the SPFx developer certificate installed, Workbench notifies you that it is configured not to load scripts from localhost. Stop the currently running process in the console window, and execute the `gulp trust-dev-cert` command in your project directory console to install the developer certificate before running the `gulp serve`command again. See details on installing a developer certificate from the [Set up your development environment](../../set-up-your-development-environment.md) article.
+  > If you do not have the SPFx developer certificate installed, Workbench notifies you that it is configured not to load scripts from localhost. Stop the currently running process in the console window, and execute the `gulp trust-dev-cert` command in your project directory console to install the developer certificate before running the `gulp serve`command again.
 
   ![SharePoint Workbench running in a SharePoint Online site](../../../images/sp-workbench-o365.png)
 
@@ -406,4 +406,4 @@ Congratulations on getting your first Hello World web part running!
 Now that your web part is running, you can continue building out your Hello World web part in the next topic, [Connect your web part to SharePoint](./connect-to-sharepoint.md). You will use the same Hello World web part project and add the ability to interact with SharePoint List REST APIs. Notice that the `gulp serve` command is still running in your console window (or in Visual Studio Code if you are using that as editor). You can continue to let it run while you go to the next article.
 
 > [!NOTE]
-> If you find an issue in the documentation or in the SharePoint Framework, please report that to SharePoint engineering by using the [issue list at the sp-dev-docs repository](https://github.com/SharePoint/sp-dev-docs/issues) or by adding a comment to this article. Thanks for your input in advance.
+> If you find an issue in the documentation or in the SharePoint Framework, please report that to SharePoint engineering by using the [issue list at the sp-dev-docs repository](https://github.com/SharePoint/sp-dev-docs/issues) or by adding a comment to this article. Thanks for your input in advance.