Add test scaffolding with jest

[sweep-ai[bot]]

Description

This PR adds test scaffolding to the fern-typescript repository, similar to what was done in the fern-python repository. The following changes have been made:

• Added jest as a dev dependency in the package.json file.
• Created a tests directory in the project.
• Added a simple no-op test file, noop.test.ts, in the tests directory.
• Modified the jest.config.ts file to include the new tests directory.

Summary of Changes

• Added jest as a dev dependency in the package.json file.
• Created a tests directory.
• Added a simple no-op test file, noop.test.ts, in the tests directory.
• Modified the jest.config.ts file to include the new tests directory.

Fixes #1.

To checkout this PR branch, run the following command in your terminal:

git checkout sweep/feature/test-scaffolding