include SVG solution information

update to include information about saving SVG from solutions. Comment made on 3/16 by a customer asking about this. 

copied below..
Goodforallpaul 
Are you going to update the icons so that they mirror the ones used on the azure.com website https://azure.microsoft.com/en-gb/solutions/architecture/

docs/resources/diagrams.md

@@ -25,6 +25,10 @@ Additional symbols for Microsoft Office and related technologies are available i
 
 A version of the diagrams used in the [Reference Architectures](../reference-architectures/index.md) is available for [download in Visio format](https://aka.ms/arch-diagrams).
 
+## Solution Architecture icons
+
+Microsoft publishes [solution architectures and accompanying diagrams](https://azure.microsoft.com/en-us/solutions/architecture/). The diagrams are in downloadable in SVG format. SVG can be opened and then modified by many tools, including Visio and PowerPoint. If you upgroup the diagram, you can get at the individual icons.  To download a diagram, right-click on it and choose "Save As". You should see an option to save as SVG. If you do not see this option, try again with a different browser. 
+
 ## 3D Blueprint Visio template
 
 A Visio template is avaliable for producing 3D (isometric) architectural diagrams.