Change the Feedback link to take you to github

[zadjii-msft]

Fixes #787.

Considering we're just duping all feedback hub issues to github, lets cut out
the middleman and take them straight here.

[carlos-zamora]

Maybe a little nitpicky but thoughts on cutting out an extra step and going to "https://github.com/microsoft/Terminal/issues/new"?

[adiviness]

Maybe a little nitpicky but thoughts on cutting out an extra step and going to "https://github.com/microsoft/Terminal/issues/new"?

I have no strong feelings one way or the other.

[miniksa]

Maybe a little nitpicky but thoughts on cutting out an extra step and going to "https://github.com/microsoft/Terminal/issues/new"?

I have two feelings about it:

1. Dropping people onto the main page might offer them the opportunity to read the issues before writing a new one.
2. I think the new issue form will offer them our templates and automatically try to find duplicates these days, so it might be a good call to go there.

I want @DHowett-MSFT to weigh in on this before merge though.

[DHowett-MSFT]

So the way it is today most closely mimics what we had before: dropping people onto the "feedback portal" where they can find everything. It's probably better for discovery than using the New Issues page.

If they can't find what they're about to report, "new issue" is just one click away. If they submit new feedback and github suggests the dupe they couldn't find, that's another chance to get them to +1 an existing report.

[miniksa]

OK let's roll with this then.