Update the wording on the Contribute Button on Desktop

[gcardonag]

Is your feature request related to a problem? Please describe.
Users can sometimes be confused around the purpose of the Contribute text and what the button does (Contribute may sometimes imply donations). In response, we would like to change the Contribute button text to "Add Site"

This would require an update to the Toolbar component.

Describe the solution you'd like
We would like the button to match the visual in this prototype: https://www.figma.com/proto/VGGqwl3Eq3GQIAO9I6LoNW/PHLASK?page-id=4510%3A29556&type=design&node-id=8105-140052&viewport=889%2C-851%2C0.09&scaling=scale-down&starting-point-node-id=8105%3A139899&show-proto-sidebar=1&mode=design

Describe alternatives you've considered
N/A

Additional context
N/A

[a-maci29]

I don't see where the Contribute button is; was this already finished, or am I missing it?