Bug: Migrate bin/index.mjs rewritten as index.js , causing CLI to fail #6897

Have you read the Contributing Guidelines on issues?

• I have read the Contributing Guidelines on issues.

Prerequisites

• I'm using the latest version of Docusaurus.
• I have tried the npm run clear or yarn clear command.
• I have tried rm -rf node_modules yarn.lock package-lock.json and re-installing packages.
• I have tried creating a repro with https://new.docusaurus.io.
• I have read the console error message carefully (if applicable).

Description

Bug: Migrate bin/index.mjs rewritten as index.js , causing CLI to fail

Reproducible demo

No response

Steps to reproduce

install migrate

Expected behavior

to run migrate

Actual behavior

fails to load as esm module needs to be .mjs not .js

Your environment

osx 10.15

Self-service

• I'd be willing to fix this bug myself.