Ability to choose meeting location

We want to reduce the environmental impact of distributed groups meeting in person. Now, we're showing the least-impactful locations, plus the home locations of each participant.

However, I could see another user need – to know the impact of the meeting place they've already determined, to see _how bad_ their meeting place is, and hopefully not repeat the mistake. Their improvement could also be a point of internal pride or external communications.

E.g., a conference organizer selects Namibia for their meeting place for mostly North American participants. The next year, using the tool, they select a place much closer to the mean location of all of the participants, resulting in a X% decrease in emissions year-over-year.

I imagine if we add the ability to select _any_ location, we'd want to not encourage users to use it – we want them to go to the least impactful place after all. It could look something like having a selector at the bottom of the list of results saying `analyze another location`, then a user could search for airports (or locations with airports).

@LanesGood @nerik @kamicut @kathrynberger thoughts?