Create simple index page so people can download our roster CSVs themselves if they want

[mpuckett159]

We are in the process of moving the source of the seed data for our database to a DigitalOcean Space. At present (and probably for the foreseeable future) DO Spaces do not offer a service that allows serving a default index.html page for a folder similar to how AWS S3 does. Because of this, I want to put together a simple web server that will be run in a container, and will present this index page for us.

The proposed folder structure will be as follows. Note that the source date of the files within a folder do not necessarily correspond to the date of the folder, which will simply be the "release date" of the files within the folder. This is just an example I don't know what the dates are for these files actually are. latest will always contain the most recent version of any file we have, files in any previous folders will not necessarily be from that specific date or different from the file in latest but it will be tagged as the "release date." This is meant to mimic a release tagging system a la Dockerhub:

spd-rosters.
├───10-12-2021
│       Auburn-WA-Police-Department.csv
│       Bellevue-WA-Police-Department.csv
│       Lakewood-WA-Police-Department.csv
│       Olympia-WA-Police-Department.csv
│       Portland-OR-Police-Bureau.csv
│       PortOfSeattle-WA-Police-Department.csv
│       Renton-WA-Police-Department.csv
│       Seattle-WA-Police-Department.csv
│       Tacoma-WA-Police-Department.csv
│       Tacoma-WA-Police-Department.csv
│       ThurstonCounty-WA-Sheriffs-Office.csv
│
├───11-18-2021
│       Auburn-WA-Police-Department.csv
│       Bellevue-WA-Police-Department.csv
│       Lakewood-WA-Police-Department.csv
│       Olympia-WA-Police-Department.csv
│       Portland-OR-Police-Bureau.csv
│       PortOfSeattle-WA-Police-Department.csv
│       Renton-WA-Police-Department.csv
│       Seattle-WA-Police-Department.csv
│       Tacoma-WA-Police-Department.csv
│       Tacoma-WA-Police-Department.csv
│       ThurstonCounty-WA-Sheriffs-Office.csv
│
├───12-29-2021
│       Auburn-WA-Police-Department.csv
│       Bellevue-WA-Police-Department.csv
│       Lakewood-WA-Police-Department.csv
│       Olympia-WA-Police-Department.csv
│       Portland-OR-Police-Bureau.csv
│       PortOfSeattle-WA-Police-Department.csv
│       Renton-WA-Police-Department.csv
│       Seattle-WA-Police-Department.csv
│       Tacoma-WA-Police-Department.csv
│       Tacoma-WA-Police-Department.csv
│       ThurstonCounty-WA-Sheriffs-Office.csv
│
└───latest
        Auburn-WA-Police-Department.csv
        Bellevue-WA-Police-Department.csv
        Lakewood-WA-Police-Department.csv
        Olympia-WA-Police-Department.csv
        Portland-OR-Police-Bureau.csv
        PortOfSeattle-WA-Police-Department.csv
        Renton-WA-Police-Department.csv
        Seattle-WA-Police-Department.csv
        Tacoma-WA-Police-Department.csv
        Tacoma-WA-Police-Department.csv
        ThurstonCounty-WA-Sheriffs-Office.csv