update homepage

[papsti]

some of the info on the site homepage is fairly out of date (e.g., @wzmli being referred to as a postdoc 😅) might be worth spending an hour updating the text a bit, at least?

[bbolker]

I also note that this repo of Mike's which is pointed to says "last updated 18 April" but not which year ... (I couldn't easily check the base repo, appears to be private and my invitation expired long ago ...)

[papsti]

also macpan2 + resources should be linked under software tools (@stevencarlislewalker)