Add reference links to sidebar text about dark-matter-graph

[yymao]

should we support arXiv ID and DOI as well?

[kadrlica]

Maybe, but I don't think it's critical. I've seen adstex, so I imagine that you already have several tools in place.

[yymao]

Right. Another question is whether the references will always be under the "references" key or will there be inline references. The former is obviously easier to implement but I wonder if there's use case for the latter.

[yymao]

I'll start with the original request (i.e., only ADS, always under references key) since that's the easiest. We can expand this feature if there's demand.

[kadrlica]

My plan was to require the developer to be consistent with ADS references always under the references key. This would also make it easier to parse the references out of the yaml file for other purposes.