As a user of the ATT&CK website, I want to be able to easily access and download ATT&CK data in various formats.

As we introduce additional ways to access raw data (CSV, Layers, etc) from the ATT&CK website, we should create an index page that allows for easy searching and downloading of data. Users may want to download all of the "group technique usage layers" at the same time instead of having to go to each group page simultaneously.

- We should create an interface which allows the user to search/filter for data to download by name and type.
- We should allow users to download individual files (E.g a single layer, CSV) from this interface.
- We should allow users to download bundles of all data of a certain type (e.g all group technique usage layers as a .zip or .tar.gz file).

We should provide a listing of the various interfaces for working with ATT&CK on the working with ATT&CK resources page. This should provide links to the STIX and Excel data as well as a listing of useful tools for working with the dataset.