• TypeScript

npm install typescript --save-dev
npx tsc --init # init a tsconfig.json

• .gitignore

# See <https://help.github.com/articles/ignoring-files/> for more about ignoring files.

# dependencies
node_modules
.pnp
.pnp.js

# testing
coverage

# production
build

# misc
.DS_Store
.env
.env.local
.env.development.local
.env.test.local
.env.production.local
.idea
npm-debug.log*
yarn-debug.log*
yarn-error.log*