message: Update README.md
  Fix broken url to legacy_README.md
diff: [![gzip size](https://img.badgesize.io/https://az416426.vo.msecnd.net/scripts/b/ai.2.min.js.svg?compression=gzip&softmax=30000&max=35000)](https://img.badgesize.io/https://az416426.vo.msecnd.net/scripts/b/ai.2.min.js.svg?compression=gzip&softmax=30000&max=35000)
  -> ***Note:*** The documentation for `applicationinsights-js` has moved [here](./legacy_README.md). If you are looking to upgrade to the new version of the SDK, please see the [Upgrade Guide](#upgrading-from-the-old-version-of-application-insights).
  +> ***Note:*** The documentation for `applicationinsights-js` has moved [here](./legacy/legacy_README.md). If you are looking to upgrade to the new version of the SDK, please see the [Upgrade Guide](#upgrading-from-the-old-version-of-application-insights).
  ## Getting Started
  1. Create an Application Insights resource in Azure by following [these instructions](https://docs.microsoft.com/en-us/azure/application-insights/app-insights-javascript?toc=/azure/azure-monitor/toc.json).
  