[Feature] Allow working on multiple docs

[hildjj]

After #6, add a list of docs down the left side. "+/-" at the top of the list (so they stay in the same place as the list grows). Label driven from doc contents. "+" adds new, from template. "-" deletes the current, after a confirmation dialog.

[hildjj]

I think all that's left on this is a better confirmation dialog. I'm currently using confirm(), but that's pretty ugly, and can be blocked by the browser. If we took a dependency on jquery-ui, this would be trivial, otherwise, I can bung something up in plain HTML.

[bifurcation]

I think we could live with the jquery-ui dependency.