Merge pull request #813 from stoneChen/master

docs: declaration files behavior for `transpileOnly: true`

Author: johnnyreilly

README.md

@@ -22,7 +22,7 @@ ts-loader works very well in combination with [babel](https://babeljs.io/) and [
 
 ### Faster Builds
 
-As your project becomes bigger, compilation time increases linearly. It's because typescript's semantic checker has to inspect all files on every rebuild. The simple solution is to disable it by using the `transpileOnly: true` option, but doing so leaves you without type checking.
+As your project becomes bigger, compilation time increases linearly. It's because typescript's semantic checker has to inspect all files on every rebuild. The simple solution is to disable it by using the `transpileOnly: true` option, but doing so leaves you without type checking and *will not output declaration files*.
 
 You probably don't want to give up type checking; that's rather the point of TypeScript. So what you can do is use the [fork-ts-checker-webpack-plugin](https://github.com/Realytics/fork-ts-checker-webpack-plugin). It runs the type checker on a separate process, so your build remains fast thanks to `transpileOnly: true` but you still have the type checking. Also, the plugin has several optimizations to make incremental type checking faster (AST cache, multiple workers).