Provide preview links for updated reusables (#50289)

Co-authored-by: Hector Alfaro <hectorsector@github.com>

src/workflows/content-changes-table-comment-cli.ts

@@ -0,0 +1,35 @@
+#!/usr/bin/env node
+
+// [start-readme]
+//
+// For testing the GitHub Action that executes
+// src/workflows/content-changes-table-comment.ts but doing it
+// locally.
+// This is more convenient and faster than relying on seeing that the
+// Action produces in a PR. Especially since
+// .github/workflows/content-changes-table-comment.yml only runs
+// on `pull_request_target`.
+//
+// To try it you need to generate a local `GITHUB_TOKEN` that has read-access
+// "content" and "pull requests" on the repo.
+// You also need to set an APP_URL which can be the domain of the
+// preview environment or just the production domain. Example:
+//
+//
+//    export GITHUB_TOKEN=github_pat_11AAAG.....
+//    export APP_URL=https://docs.github.com
+//    tsx src/workflows/content-changes-table-comment-cli.ts github docs-internal main 4a0b0f2
+//
+// [end-readme]
+
+import { program } from 'commander'
+import main from '@/workflows/content-changes-table-comment'
+
+program
+  .description('Produce a nice table based on the branch diff')
+  .arguments('owner repo bash_sha head_sha')
+  .parse(process.argv)
+
+const args = program.args
+const [owner, repo, baseSHA, headSHA] = args
+console.log(await main(owner, repo, baseSHA, headSHA))