Basic Project Setup

[nhaef]

This PR contributes a basic project setup with a few dependencies which we can use during the development of ets. Here is an overview of the key changes introduced in this PR:

• Created package.json
• Created .editorconfig to maintain a consistent code style. See https://editorconfig.org/
• Installed and configured prettier, so that the code style can be enforced automatically
• Installed and configured eslint with @typescript-eslint/recommended and a few additional rules, to quickly find problems in our code. See https://eslint.org/ and https://typescript-eslint.io/
• Installed and configured typescript
• Installed and configured ts-mocha for testing
• Installed and configured nyc to calculate test coverage. See https://istanbul.js.org/