README link fixes (facebook#5326)

* Fix broken link in main README

* Fix incorrect link in user guide README

Author: davidgilbertson

README.md

@@ -130,7 +130,7 @@ The [User Guide](https://github.com/facebook/create-react-app/blob/master/packag
 - [Folder Structure](https://github.com/facebook/create-react-app/blob/master/packages/react-scripts/template/README.md#folder-structure)
 - [Available Scripts](https://github.com/facebook/create-react-app/blob/master/packages/react-scripts/template/README.md#available-scripts)
 - [Supported Browsers](https://github.com/facebook/create-react-app/blob/master/packages/react-scripts/template/README.md#supported-browsers)
-- [Supported Language Features and Polyfills](https://github.com/facebook/create-react-app/blob/master/packages/react-scripts/template/README.md#supported-language-features-and-polyfills)
+- [Supported Language Features and Polyfills](https://github.com/facebook/create-react-app/blob/master/packages/react-scripts/template/README.md#supported-language-features)
 - [Syntax Highlighting in the Editor](https://github.com/facebook/create-react-app/blob/master/packages/react-scripts/template/README.md#syntax-highlighting-in-the-editor)
 - [Displaying Lint Output in the Editor](https://github.com/facebook/create-react-app/blob/master/packages/react-scripts/template/README.md#displaying-lint-output-in-the-editor)
 - [Formatting Code Automatically](https://github.com/facebook/create-react-app/blob/master/packages/react-scripts/template/README.md#formatting-code-automatically)

packages/react-scripts/template/README.md

@@ -96,7 +96,7 @@ You can find the most recent version of this guide [here](https://github.com/fac
   - [S3 and CloudFront](#s3-and-cloudfront)
   - [Surge](#surge)
 - [Advanced Configuration](#advanced-configuration)
-- [Troubleshooting](#troubleshooting)
+- [Troubleshooting](#troubleshooting-1)
   - [`npm start` doesn’t detect changes](#npm-start-doesnt-detect-changes)
   - [`npm test` hangs or crashes on macOS Sierra](#npm-test-hangs-or-crashes-on-macos-sierra)
   - [`npm run build` exits too early](#npm-run-build-exits-too-early)