add github star notice on Getting Started widget

[tabacitu]

WHY

BEFORE - What was wrong? What was happening before this PR?

We weren't asking people to give us a Star on Github.

AFTER - What is happening after this PR?

We are doing that, in our Getting Started widget.

HOW

How did you achieve that, in technical terms?

Text and link in the blade file that shows how to Get Started using Backpack.

Is it a breaking change?

No

How can we test the before & after?

You don't need to. Here's how it looks:

[tabacitu]

Thanks for the suggestion Karan!

[karandatwani92]

@tabacitu
The placement is much inside/hidden. Can we dedicate a step to it before the last one? It will be much more visible.

Also, I see a problem with step numbering:

[tabacitu]

Fixed the numbering problem - 82d6d72 - thanks.

I don't think making it "more visible" would help. For example, we can put it on every page - that would be most visible. Would anybody click and give us a star? No, because we'd be annoying the hell out of people, and when we are seeing each page they do not CARE what we want from them. They care about that page. So we are not looking for "visible" here. We are looking to ask the person for star at the right moment in their customer journey. THIS POINT, after the user has gotten started and created a model, I think is a great place. We should look for more places like that - not try to add this everywhere and "make it visible" in the hopes that people will click. This is not an advertisment. It's an ask.