added some doc info

packages/typescript/README.md

@@ -90,6 +90,20 @@ By default, patterns resolve against the rootDir set in your TS config file.
 
 This can fix plugin errors when parsing files outside the current working directory (process.cwd()).
 
+### `transpilationMode`
+
+Type: `'full' | 'declarationOnly' | 'transpileOnly' | 'none'`<br>
+Default: `'full'`
+
+* `'full'` always transpile code and emit declarations
+* `'declarationOnly'` only emit declarations, raw typescript code will be passed to next plugin
+  * this is useful if the next plugin is `@rollup/plugin-babel` and you have it set up to transpile typescript via `babel-plugin-typescript`
+  * this is effectively the same as the `tsc --emitDeclarationOnly && babel src --out-dir dist`
+  * Also useful if you're having typescript emit declaration for your js file, but don't have any ts files to transpile
+* `'transpileOnly'` transpile code, but don't emit declarations. Type errors will still be displayed
+* `'none'` no transpilation or declarations. Raw typescript code will be passed to the next plugin. Type errors will still be displayed
+  * This is useful if you want type errors to display, but don't want declarations files, and then have `@rollup/plugin-babel` do all your transpilation
+
 ### `tsconfig`
 
 Type: `String` | `Boolean`<br>