yarn add gatsby-plugin-typescript
yarn add typescript --dev
# npm
npm i gatsby-plugin-typescript
npm i typescript --save-devgatsby new gatsby-starter-default-typescript https://github.com/andykenward/gatsby-starter-default-typescriptCopyInstall command: copy code to clipboardgatsby new gatsby-starter-typescript https://github.com/haysclark/gatsby-starter-typescriptCopyInstall command: copy code to clipboardnpm init gatsby -ts