Add callout on how we present municipal election results

[longhotsummer]

The data is correct, what's confusing is the way we present the data for municipal elections. We show PR and Ward election numbers combined.

Wikipedia says this about the election results:

The councils of metropolitan and local municipalities are elected by a system of mixed-member proportional representation, in which half of the seats in each municipality are elected on the first-past-the-post system in single-member wards and the other half of the seats are allocated according to the proportional representation (PR) system. The latter takes into account the number of ward seats won by a party, and ensures that the final number of seats held by that party is proportional to their percentage of the total vote.

So we're showing the total combine votes. For people who don't understand PR and Ward councillor votes (most people), this is generally most meaningful.

I think we should put a callout there indication that we're showing combined votes to help make it clearer.