Fold Help & Community page into hamburger menu (and some bug fixes)

The Help & Community page has always been weird and I think people have trouble finding the Discord and Forum links because they’re hidden away there. I’ve now updated the hamburger menu to just have those links within it and done away with that page entirely.

I also made a couple style tweaks that I hope makes the hamburger menu look a little better.

Finally I fixed a bug that @xymostech reported awhile back: Strange behavior of selection when choosing new options. It’s now possible to select tokens that are within a selection area (but not yet selected).