feat: publish ESM version (#473)

**Which problem is this pull request solving?**

This module doesn't currently publish an ESM version. It's hard to use
this in ES modules, because it needs to be dynamically imported, but it
imports node builtins that can't be dynamically imported.

**Describe the solution you've chosen**

This PR uses `tsup` to build both cjs and esm. It also adds publint and
arethetypeswrong to check the output, and removes the one-line
`is-promise` CJS dependency.

Author: ascorbic

.github/workflows/workflow.yml

@@ -23,17 +23,29 @@ jobs:
     steps:
       - name: Git checkout
         uses: actions/checkout@v3
-      - name: Node.js ${{ matrix.node-version }}
+      - name: Node.js latest
         uses: actions/setup-node@v3
         with:
-          node-version: ${{ matrix.node-version }}
+          node-version: '*'
           cache: 'npm'
           check-latest: true
       - name: Install dependencies
         run: npm ci
       - name: Linting
         run: npm run format:ci
         if: "${{ matrix.node-version == '*' }}"
+      - name: Build
+        run: npm run build
+      - name: Node.js ${{ matrix.node-version }}
+        uses: actions/setup-node@v3
+        if: "${{ matrix.node-version != '*' }}"
+        with:
+          node-version: ${{ matrix.node-version }}
+          cache: 'npm'
+          check-latest: true
+      - name: Install dependencies ${{ matrix.node-version }}
+        run: npm ci
+        if: "${{ matrix.node-version != '*' }}"
       - name: Tests
         run: npm run test:ci
       - name: Get test coverage flags