Adds option for archiving local elections

[rentry]

This isn't ideal, but I thought I would send it up for review.

This branch adds the following:

• Introduces new subfolder for local election csvs in data directory
• New collection for local elections with a markdown file for each local election
  • Local election front matter points to the respective local election csv in _data directory
• Creates _include for search input and table loop, in which the data file declaration references individual local election front matter

I'm not convinced this is the best approach, but it does have some advantages:

• We can loop through the collection and output results in the archive
• Allows for a crosswalk of metadata to csv data files

This method will require creating a new .md file in the collection with properly formatted front matter.

[rentry]

Example of local page is at path /local-archive/local-2019-11/

[inomyabcs]

I think I prefer this approach. I would recommend adding the clear_local_ballot perl script to blank out the csv ballot column for each new election, unless there is a cleaner way to do it.

[shannonmcharg]

Looks good. We just need to add a way to link to the archive local pages from the archive.

[rentry]

☝️ That commit adds a loop through local collection to add to archive page.

• Could use page-level nav to jump to local
• Relies on the election key in front matter

[inomyabcs]

Thanks