This directory contains historical data about the TL schema.

That is, it contains history of the schema over time and pre-calculated difference
between consecutive versions.

The files are generated with scripts and are not in the repository.

To generate the files, execute scripts from `../scripts`:
1. `fetch-history.js`
2. `fetch-older-layers.js`
3. `generate-type-history.js`

To update files:
1. `fetch-history.js`
2. `generate-type-history.js`