Link to canonical info on a technology

[sdgluck]

Link from technologies to a canonical source of information about that technology.

There are a number of technologies on the page that I don't recognise (e.g. Risograph, Preps, Tharsten). It'd be great to be able to easily found out more information about them.

(Copied over from https://wiki.coops.tech/wiki/CoTech_WordPress#Wishlist)