Add a reminder about include/exclude options (#275)

* Add a reminder about include/exclude options [skip ci]

* include note about adding plugin [skip ci]

README.md

@@ -170,6 +170,8 @@ This option is useful if there is a bug in a native implementation, or a combina
 
 For example, Node 4 supports native classes but not spread. If `super` is used with a spread argument, then the `transform-es2015-classes` transform needs to be `include`d, as it is not possible to transpile a spread with `super` otherwise.
 
+> NOTE: The `include` and `exclude` options _only_ work with the [plugins included with this preset](https://github.com/babel/babel-preset-env/blob/master/data/plugin-features.js); so, for example, including `transform-do-expressions` or excluding `transform-function-bind` will throw errors. To use a plugin _not_ included with this preset, add them to your [config](https://babeljs.io/docs/usage/babelrc/) directly.
+
 ### `exclude`
 
 `Array<string>`, defaults to `[]`.