Change speaking page sort order

[bridgetkromhout]

The sort order for the page introduced in devopsdays/devopsdays-theme#117 defaults to column 3 - in order of when the conference is being held. That seems like it's not the most useful default, since someone coming to this page might reasonably expect the CFP closing soonest to be atop the list (which would mean sorting by column 2).

[mattstratton]

We haven't bikeshed over this yet, but as a user, I would expect this to be default sorted by CFP dates not event dates.

[bridgetkromhout]

This is trickier than the most obvious solution (of changing https://github.com/devopsdays/devopsdays-theme/blob/master/layouts/partials/speaking.html#L6 to reference the cfp end date) because that won't be set in every case.

[mattstratton]

Does the page even work if cfp_endate isn't set?

[bridgetkromhout]

If cfp end_date isn't set, then that city just won't show up in this list, in theory. I'll do some testing (out of time now).

[bridgetkromhout]

The page works fine when events don't have cfp_date_end set - they just don't show up. However, I think the map sorting in ascending order is using key, not value, which doesn't do what we want. Further investigation is warranted.

[bridgetkromhout]

If it's possible to make the page open with a default of "and then select and sort by the middle column" that would be an acceptable v1.0 solution for me. (Honestly I don't think this is terrible enough to hold up the release overall.)

[bridgetkromhout]

Clarification: I don't think we hold 1.0 on this.

[bridgetkromhout]

Related to devopsdays/devopsdays-theme#340

[mattstratton]

#8218 might be the fix for this - with this change, the CFP page is sorted by CFP date by default now. @bridgetkromhout if this is satisfactory to you, we can close this issue.

[mattstratton]

I am pretty sure @bridgetkromhout told me in Slack this was able to be closed. If not, feel free to re-open :)