Merge pull request #916 from SteveL-MSFT/echo-description

Add description to Echo resource

Author: SteveL-MSFT

dscecho/echo.dsc.resource.json

@@ -2,6 +2,7 @@
     "$schema": "https://aka.ms/dsc/schemas/v3/bundled/resource/manifest.json",
     "type": "Microsoft.DSC.Debug/Echo",
     "version": "1.0.0",
+    "description": "Echo resource for testing and debugging purposes",
     "get": {
         "executable": "dscecho",
         "args": [