release: add release log generation script (#54006)

Add script of generating release log. To access the changelog just run the below script (copy content with `pbcopy` on MacOS)

```js
node ./scripts/generate-release-log.mjs | pbcopy
```

Author: huozhi

scripts/generate-release-log.mjs

@@ -0,0 +1,117 @@
+import fetch from 'node-fetch'
+
+async function main() {
+  const releasesArray = await fetch(
+    'https://api.github.com/repos/vercel/next.js/releases?per_page=100'
+  ).then((r) => r.json())
+
+  const allReleases = releasesArray
+    .map(({ id, tag_name, created_at, body }) => ({
+      id,
+      tag_name,
+      created_at,
+      body: body
+        .replace(/\r\n/g, '\n')
+        .split('\n')
+        .map((e) => e.trim()),
+    }))
+    .sort((a, b) => a.created_at.localeCompare(b.created_at))
+
+  // targetVersion format is `13.4.15-`, generating changes for all 13.4.15-* canary releases
+  const targetVersion = /v(.*?-)/
+    .exec(allReleases.filter((e) => /v.*?-/.exec(e.tag_name)).pop().tag_name)
+    .pop()
+
+  const releases = allReleases.filter((v) => v.tag_name.includes(targetVersion))
+
+  const lineItems = {
+    '### Core Changes': [],
+    '### Minor Changes': [],
+    '### Documentation Changes': [],
+    '### Example Changes': [],
+    '### Misc Changes': [],
+    '### Patches': [],
+    '### Credits': [],
+  }
+
+  Object.keys(lineItems).forEach((header) => {
+    releases.forEach((release) => {
+      const headerIndex = release.body.indexOf(header)
+
+      if (!~headerIndex) return
+
+      let headerLastIndex = release.body
+        .slice(headerIndex + 1)
+        .findIndex((v) => v.startsWith('###'))
+
+      if (~headerLastIndex) {
+        headerLastIndex = headerLastIndex + headerIndex
+      } else {
+        headerLastIndex = release.body.length - 1
+      }
+
+      if (header === '### Credits') {
+        release.body.slice(headerIndex, headerLastIndex + 1).forEach((e) => {
+          const re = /@[a-z\d](?:[a-z\d]|-(?=[a-z\d])){0,38}/gi
+          let m
+
+          do {
+            m = re.exec(e)
+
+            if (m) {
+              lineItems[header].push(m.pop())
+            }
+          } while (m)
+        })
+      } else {
+        release.body.slice(headerIndex, headerLastIndex + 1).forEach((e) => {
+          if (!e.startsWith('-')) {
+            return
+          }
+          lineItems[header].push(e)
+        })
+      }
+    })
+  })
+
+  let finalMessage = []
+
+  Object.keys(lineItems).forEach((header) => {
+    let items = lineItems[header]
+
+    if (!items.length) {
+      return
+    }
+    finalMessage.push(header)
+    finalMessage.push('')
+
+    if (header === '### Credits') {
+      items = [...new Set(items)]
+      let creditsMessage = `Huge thanks to `
+
+      if (items.length > 1) {
+        creditsMessage += items.slice(0, items.length - 1).join(`, `)
+        creditsMessage += `, and `
+      }
+      creditsMessage += items[items.length - 1]
+      creditsMessage += ` for helping!`
+
+      finalMessage.push(creditsMessage)
+    } else {
+      items.forEach((e) => finalMessage.push(e))
+    }
+
+    finalMessage.push('')
+  })
+
+  return {
+    version: targetVersion.slice(0, -1),
+    firstVersion: releases[0].tag_name,
+    lastVersion: releases[releases.length - 1].tag_name,
+    content: finalMessage.join('\n'),
+  }
+}
+
+main().then((result) => {
+  console.log(result.content)
+})