Change "Get Started with Plover" link on index page

[keikoro]

https://www.openstenoproject.org/plover/ concludes with a button/link labelled "Get Started with Plover".

It links to this GitHub page which states it has moved and links to a Wiki page.

To save people a click, the source of the link:
https://github.com/openstenoproject/openstenoproject.github.io/blob/3230501a71c39613306680bdd623a34469a1cf10/index.html#L117
ought to get changed to https://plover.wiki/index.php/Beginner%27s_Guide.

[keikoro]

Hold on, that's not the actual index page, is it? I... searched this org for the button label, so I'm guessing that page is hosted elsewhere?