docs(configuration/output): Warn about module output being not usable in webpack4

Author: jtomaszewski

src/content/configuration/output.mdx

@@ -1970,7 +1970,7 @@ module.exports = {
 };
 ```
 
-W> `output.module` is an experimental feature and can only be enabled by setting [`experiments.outputModule`](/configuration/experiments/#experiments) to `true`.
+W> `output.module` is an experimental feature and can only be enabled by setting [`experiments.outputModule`](/configuration/experiments/#experiments) to `true`. [One of the known problems](https://github.com/webpack/webpack/issues/11277#issuecomment-992565287) is that such a library can't be consumed by webpack4-based (and possibly other too) applications.
 
 ## output.path