Add a `lucky dip` button

[Sparrow0hawk]

Some wards may never be selected, so offering a lucky dip button maybe be a way of encouraging calls to other wards.

Kinda contravenes the point of prioritising volunteer mobilisation but might be nice.

[Sparrow0hawk]

This line here is a good candidate for this

mynearestleedsmarginal/server.R

Line 93 in 3f7dbbc

a <- google_geocode(as.character(lst[sample(c(1,2,3), size=1),]), key = key1)