Add list indices to institutes

[jkrenzer]

Problem: We get the institutes per author as numeric indices, which is fine. But as we cannot enumerate in pandoc template $for loops, it is not trivial to link or reference against the institutes. Basically we cannot get a hold of the institutes index in pandoc template language.

Solution: Adding the index of the institute to the institute-object helps in getting this references straight. Now we can write, for example, a html-template and make use of anchor-links and id's.

[jgm]

Note that in the next version of pandoc you will be able to access the indices in pandoc's templates.

[jkrenzer]

That is good news, as I prefer to use templates for document-composition whenever possible. Thank you.

But still I would propose explicitly exposing attributes which we use for references.

[tarleb]

Thanks, this seems like a good idea.