Reintroduce showing capital cities on world map

[edwardchalstrey1]

See MajidBenam#11

The issue is that many Seshat pages with a recorded capital lack accompanying lat/lon coords. So this may not be worth enabling until such time as RAs have added a lot more capital data.

• Could it be worth using some kind of automated method to extract capital coords for city names that can be found in google maps, open street maps etc?

Examples

core/polity/571
core/polity/575