Create a vignette to showcase as_epidist Ebola example linking multiple entries

[cm401]

Currently it is challenging to link different parameter entries from epireview.
This vignette will show how to do this based on linkage by paper id.

@annecori and Anton have an example, which we need to convert into a vignette.

[joshwlambert]

Thanks for posting @cm401. The current data_from_epireview.Rmd vignette in {epiparameter} contains a section on multi-row entries from {epireview}. Does this cover the request in this issue or is there another aspect that you'd like to include?

The current example uses Marburg but this issue mentions Ebola, is there a specific aspect of linking multi-entry Ebola data that is different from the other pathogens, or would adding an example of multi-entry Ebola data to show the process is the same across pathogens in {epireview}?

I'm more than happy to update the vignette with the required changes once I have a better idea of the specific improvments.

[joshwlambert]

Removing this from the v0.2.0 project as there is not enough time before the next release to draft the vignette, and the contents of the vignette still need to be ironed out.