(docs/fix): remove outdated language about custom Babel configs (#467)

- as of v0.9, custom Babel configs are merged with TSDX's transforms
- remove language about Babel entirely from comparison docs as Babel
  support does not entail JS support (and at least some JS is already
  supported anyway)

README.md

@@ -384,7 +384,7 @@ TSDX is ripped out of [Formik's](https://github.com/jaredpalmer/formik) build to
 
 - TSDX includes out-of-the-box test running via Jest
 - TSDX includes a bootstrap command and default package template
-- TSDX is 100% TypeScript focused. While yes, TSDX does use Babel to run a few optimizations (related to treeshaking and lodash), it does not support custom babel configurations.
+- TSDX is 100% TypeScript focused
 - TSDX outputs distinct development and production builds (like React does) for CJS and UMD builds. This means you can include rich error messages and other dev-friendly goodies without sacrificing final bundle size.
 
 ## API Reference