Don't gitignore the generated types to ensure code integrity

The .contentlayer folder includes two types of auto-generated resources:

- The JSON files generated from the underlying content.
- The ts files generated from the Contentlayer schema.

Current architecture assumes that both types of resources should be gitignored.

What I would like to suggest is to not git-ignore the generated types and commit them with the source code. Maybe into a separate `src/types` folder or something similar.

The types are used everywhere within the code, and therefore are being an integral part of it. Having the code without its types makes the impression that the code is incomplete.

For example, opening a GitHub's web-based editor (`github.dev`) with project powered by Contentlayer unveils a code that extensively uses types, but no types are available within the repo. And it creates an impression that the integrity of the code is not complete.