List location in info summary box at top of the main page.

I usually end up adding the workshop location to the info box at the top of the page, so that learners don't need to scan for it in the "General Information" section. For two examples, see [2016-10-06-harvard](https://sorgerlab.github.io/2016-10-06-harvard/), and [2016-04-29-ucsf](https://bsmith89.github.io/2016-04-29-ucsf/).

It fits (both spatially and logically) in the first column with the date and time. It would also be useful to link to a map service, but I'm not sure if it should be Google Maps or Open Street Maps.

Sorry if I missed where this has been discussed before. I can submit a pull request based on what I've done for workshops in the past, but I may not be the best person to choose an implementation for everyone.