SPF229802: Don't include the same modules in multiple bundles

By default, when you require modules in your SharePoint Framework Client Side Web Part, unless specified otherwise, these modules will be included in your Web Part's bundle. As a result, if you built two Web Parts using jQuery, your users will be downloading jQuery twice - one for each Web Part.
    
A better approach would be to make a separate bundle for jQuery, and other modules shared among multiple Web Parts, and reference that bundle from your Web Parts. Such bundles are commonly referred to as Dll bundles. Using Dll bundles your users would download the shared resources only once. Other Web Parts, using the same resources, could benefit of the Dll bundles already cached in their browser.

• Building dll-code in SharePoint Framework
• Building Webpack Dll bundles using the DllPlugin
• Using Webpack Dll bundles with the DllReferencePlugin