Updated the logged-out homepage's screencast

Just put out a release that updates the video that appears when you visit shmeppy.com without being logged in. It was pretty out-of-date and I wanted to feature at least the anti-label collision features as well as resizable tokens since both of those have landed since I made that video.

I also fixed a visual bug where the grid guides (the little dots all over the map) weren’t being rendered on top of edges correctly.

Finally, I created the Testimonials category in this forum. It’ll be awhile before I start integrating testimonials into the logged-out homepage, but I wanted to get a head start on collecting them here.