feat(payments): upgrade Web Payments SDK to v1 (#10)

BREAKING CHANGE: general availability release

* chore: use node v16 for development

* fix: exporting types

* docs: tsdx example

showcases importing types

* chore(deps): upgrade @square/web-payments-sdk-types

.github/workflows/ci.yml

@@ -17,7 +17,7 @@ jobs:
       - name: Set up Node
         uses: actions/setup-node@v2
         with:
-          node-version: '15' # keep in sync w/ .nvmrc
+          node-version: '16' # keep in sync w/ .nvmrc
 
       - name: Get npm cache directory
         id: npm-cache

.nvmrc

@@ -1 +1 @@
-v15.8
+v16

README.md

@@ -10,7 +10,7 @@
 
 ### Getting Started
 
-This project uses Node v15 as defined by `.nvmrc` to take advantage of npm@7. You can use [nvm](https://github.com/nvm-sh/nvm) to install the correct version:
+This project uses Node v16 as defined by `.nvmrc` to take advantage of npm@7. You can use [nvm](https://github.com/nvm-sh/nvm) to install the correct version:
 
 ```sh
 nvm install $(cat .nvmrc)

examples/tsdx/.gitignore

@@ -0,0 +1 @@
+dist

examples/tsdx/README.md

@@ -0,0 +1,91 @@
+# TSDX
+
+Use [TSDX](https://tsdx.io/), "zero-config CLI for TypeScript package development", to build a simple payment form library with Square Web SDK.
+
+## How to use
+
+Clone, install, and start:
+
+```sh
+# clone from github
+git clone https://github.com/square/web-sdk.git
+# go to example
+cd examples/tsdx
+# install dependencies
+npm install
+# start development server
+npm start
+```
+
+This builds to `/dist` and runs the project in watch mode so any edits you save inside `src` causes a rebuild to `/dist`.
+
+---
+
+## TSDX User Guide
+
+Congrats! You just saved yourself hours of work by bootstrapping this project with TSDX. Let’s get you oriented with what’s here and how to use it.
+
+> This TSDX setup is meant for developing libraries (not apps!) that can be published to NPM. If you’re looking to build a Node app, you could use `ts-node-dev`, plain `ts-node`, or simple `tsc`.
+
+> If you’re new to TypeScript, checkout [this handy cheatsheet](https://devhints.io/typescript)
+
+### Commands
+
+TSDX scaffolds your new library inside `/src`.
+
+To run TSDX, use:
+
+```bash
+npm start # or yarn start
+```
+
+This builds to `/dist` and runs the project in watch mode so any edits you save inside `src` causes a rebuild to `/dist`.
+
+To do a one-off build, use `npm run build` or `yarn build`.
+
+To run tests, use `npm test` or `yarn test`.
+
+### Configuration
+
+Code quality is set up for you with `prettier`, `husky`, and `lint-staged`. Adjust the respective fields in `package.json` accordingly.
+
+#### Jest
+
+Jest tests are set up to run with `npm test` or `yarn test`.
+
+#### Bundle Analysis
+
+[`size-limit`](https://github.com/ai/size-limit) is set up to calculate the real cost of your library with `npm run size` and visualize the bundle with `npm run analyze`.
+
+##### Setup Files
+
+This is the folder structure we set up for you:
+
+```txt
+/src
+  index.tsx       # EDIT THIS
+/test
+  blah.test.tsx   # EDIT THIS
+.gitignore
+package.json
+README.md         # EDIT THIS
+tsconfig.json
+```
+
+#### Rollup
+
+TSDX uses [Rollup](https://rollupjs.org) as a bundler and generates multiple rollup configs for various module formats and build settings. See [Optimizations](#optimizations) for details.
+
+#### TypeScript
+
+`tsconfig.json` is set up to interpret `dom` and `esnext` types, as well as `react` for `jsx`. Adjust according to your needs.
+
+## Module Formats
+
+CJS, ESModules, and UMD module formats are supported.
+
+The appropriate paths are configured in `package.json` and `dist/index.js` accordingly. Please report if any issues are found.
+
+## Named Exports
+
+Per Palmer Group guidelines, [always use named exports.](https://github.com/palmerhq/typescript#exports) Code split inside your React app instead of your React library.