dump outdated content (#819)

Author: filiptammergard

README.md

@@ -168,7 +168,7 @@ Any other tips? Please contribute on this topic! [We have an ongoing issue here
 Compiling large TS projects can get slow. Here are some tips:
 
 - We have a dedicated repo tracking TS speed recommendations: https://github.com/typescript-cheatsheets/speed
-- Use [TS 3.0 Project references](https://react-typescript-cheatsheet.netlify.app/docs/advanced/patterns_by_version#typescript-30)
+- Use [TypeScript Project references](https://www.typescriptlang.org/docs/handbook/project-references.html)
 - Check the official [TS performance wiki guidelines](https://github.com/microsoft/TypeScript/wiki/Performance) - note that [Dan Rossenwasser says to take it with a grain of salt](https://news.ycombinator.com/item?id=25199070)
 - Webpack ([see CRA diff](https://gist.github.com/jaredpalmer/d3016701589f14df8a3572df91a5754b)):
   - set `output.pathinfo = false`

docs/advanced/misc-concerns.md

@@ -243,7 +243,7 @@ ReactDOM.render(
 );
 ```
 
-As of [TS 2.9](#typescript-29), you can also supply the type parameter in your JSX to opt out of type inference:
+You can also supply the type parameter in your JSX to opt out of type inference:
 
 ```tsx
 ReactDOM.render(