add species high-level summary

[nlwashington]

being the cross-species people, i think it'd be great to add a high-level summary of the cross-species data that we have in our database. some basic statistics and/or fun facts.

we could include:

• number of annotated species, and number of genes, genotypes/strains/breeds, and variants annotated
• number of diseases curated with phenotypes
• an (descending) ordered list of diseases (top 10?) and the number/breadth of models for it as an entry point.
• most-annotated leaf-thing for each type (disease, gene, phenotype, etc)

here's an example that OMIA includes on their front page:

we could do this with some little charts and/or tables. might be nice and splashy.

is this something we should just run a script to produce a table of stats? or are there special solr queries that can give these kinds of results?

[cmungall]

For solr, ideally we'd have the equivalent of the bioentity index we have for GO (one entry per association subject, closure list for object, plus direct objects). Nor do we have an index with one entry per (subj,obj-closure) tuple, what in GO we call the annotation_aggregate (not v informative name).

In theory not so hard to add. I would do this generically for all yaml views, rather than per view.

cc @kltm