Broken link for simple-Linux-VM instructions

[simple-Linux-VM](https://github.com/Azure/azure-quickstart-templates/tree/master/marketplace-samples/simple-Linux-VM)

### Broken Link, STILL!

"The second step is start authoring the createUiDefinition file. The schema for the createUiDefinition elements can be found here: https://github.com/azure/azure-portal-createuidefinition " <---Broken link - why is this taking so long for you guys to fix?

Start with the simple-Linux-VM instructions linked in the issue and inspect the step that references the createUiDefinition schema. Verify the destination URL, replace the broken reference with the correct link, and confirm the rendered instructions contain a working link.

Written by the indexing model from the issue text.