General Improvements (#70)

# General Improvements

> This is a classic @GrantBirki drive-by PR 🚗

This pull request does the following:

- Lightly updates and formats a few existing Actions workflows
- Adds a new `package-check` workflow to validate the contents of the
`dist/` directory have been properly built
- Uses a `.node-version` file so that local development and Actions
remain on the same pinned version of node
- Adds status badges to the readme for visual effect ⭐ 🎨

badges/coverage.svg

@@ -0,0 +1,25 @@
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" width="106"
+    height="20" role="img" aria-label="Coverage: 100%">
+    <title>Coverage: 100%</title>
+    <linearGradient id="s" x2="0" y2="100%">
+        <stop offset="0" stop-color="#bbb" stop-opacity=".1" />
+        <stop offset="1" stop-opacity=".1" />
+    </linearGradient>
+    <clipPath id="r">
+        <rect width="106" height="20" rx="3" fill="#fff" />
+    </clipPath>
+    <g clip-path="url(#r)">
+        <rect width="63" height="20" fill="#555" />
+        <rect x="63" width="43" height="20" fill="#4c1" />
+        <rect width="106" height="20" fill="url(#s)" />
+    </g>
+    <g fill="#fff" text-anchor="middle" font-family="Verdana,Geneva,DejaVu Sans,sans-serif"
+        text-rendering="geometricPrecision" font-size="110">
+        <text aria-hidden="true" x="325" y="150" fill="#010101" fill-opacity=".3"
+            transform="scale(.1)" textLength="530">Coverage</text>
+        <text x="325" y="140" transform="scale(.1)" fill="#fff" textLength="530">Coverage</text>
+        <text aria-hidden="true" x="835" y="150" fill="#010101" fill-opacity=".3"
+            transform="scale(.1)" textLength="330">100%</text>
+        <text x="835" y="140" transform="scale(.1)" fill="#fff" textLength="330">100%</text>
+    </g>
+</svg>