add build steps for CDN distribution

scripts/update-cdn.js

@@ -0,0 +1,32 @@
+import { readFileSync, writeFileSync } from 'fs'
+import updateSection from 'update-section'
+import { name, main, version } from '../package.json'
+
+console.log(`Updating CDN info to latest v${version} release...`)
+
+const readmePath = './README.md'
+const cdnUrl = `https://unpkg.com/${name}@${version}/${main}`
+const minifiedUrl = cdnUrl.replace('.js', '.min.js')
+
+const content = readFileSync(readmePath, 'utf-8')
+
+const update = `
+  <!-- start CDN generator - do **NOT** remove this comment -->
+  **Uncompressed:**
+  > ${cdnUrl}
+
+  **Minified:**
+  > ${minifiedUrl}
+  <!-- end CDN generator - do **NOT** remove this comment -->
+`.trim().replace(/ {2}/gm, '')
+
+const updated = updateSection(
+  content,
+  update,
+  (line) => (/<!-- start CDN generator/).test(line),
+  (line) => (/<!-- end CDN generator/).test(line)
+)
+
+writeFileSync(readmePath, updated)
+
+console.log('CDN info updated.')