Add information about recon specs, actions, and interfaces to model pages

[tsalo]

This is something we talked about in the recent hackathon, but decided was out of scope for the first round of PRs. I'd like to link to the API information for relevant interfaces and workflows on the model pages, as well as to document any relevant recon specification fields.

[mattcieslak]

I've been thinking about this today. I'm leaning toward the docstrings of the individual "nodes" to explain which parameters are used and what computations are done in what order. Then the higher-level docs like builtin_workflows.rst can link to the individual "nodes" they string together