Record all static CSV and JSON assets needed to run front-end.

[mradamcox]

We need to audit the current state of static CSV and JSON files that are used to drive the frontend. I believe there is content in the repo that isn't actually used anymore, so this ticket can cover removing that content, but also should produce a list (in a comment below is fine) of all files that are needed.

Ultimately, the hope is that we can streamline these files and generate them directly from the backend resource definitions.

[bucketteOfIvy]

There are essentially 5 relevant files and folders:

• meta/csvFiles.js : used by the download.js filtering tool to select which files to download.
• meta/variables.js : docs/index.js references the markdown, Source, Spatial Scale, and Variable Proxy properties of each entry, as well as the overarching data category; components/map/VariablePanel.js retrieves relevant markdown URLs for the display variable by using the markdownPrefix to join map-config.js's numerator, and markdown to get the actual markdown file.
• config/variables.json : referenced by map-config.js and used to control the style of the map (i.e. number of bins, variables, binning style, color scale, etc).
• map-config.js : referenced by index.js and default.js to allow the map to connect geojsons to attribute data files
• public/ : has two subdirectories, csv/ and geojson/ which contain the csv attribute tables and geojson geometries, respectively

With regards to unused but present files of this sort:

• config/variables.csv, meta/csvFiles.csv : appears to be csv versions of variables.json and csvFiles.js.
• meta/docCrosswalks.js, meta/stateInfo.js, meta/zipRange.js : files referenced by the unfinished restful API.