fyi: 404 link in readme + fix

[FrissAnalytics]

Hi Matthew,

hope your doing well! incredible tool!

fyi: one of the links in the readme User-contributed resources gives a 404, it's the ref to Jack Dougherty.

This gives a 404:

https://datavizforall.org/convert-edit-join-and-dissolve-with-mapshaper-org.html

I'm guessing it now should be this one:

https://handsondataviz.org/mapshaper.html

kind regards, Herman

[mbloch]

Thanks for reporting this... fixed now.