Make the "useOmnisharp" option order first

The rest of the options won't do anything unless this is set, so
we should probably make that be the easiest one to find.

Author: jasonmalinowski

package.json

@@ -710,7 +710,8 @@
           "dotnet.server.useOmnisharp": {
             "type": "boolean",
             "default": false,
-            "description": "Switches to use the Omnisharp server for language features when enabled (requires restart). This option will not work with C# Dev Kit"
+            "description": "Switches to use the Omnisharp server for language features when enabled (requires restart). This option will not work with C# Dev Kit.",
+            "order": 0
           },
           "csharp.format.enable": {
             "type": "boolean",