[PSR-19]: @throws bubbleling

[Anton Fedonyuk]

Tag description not contain information about  bubbling errors/exceptions i.e.  errors/exceptions throwed in calling functions.

I think we need to add note: @throws tags adding for errors/exceptions thrown directly in commented function/method.

Why @throws tags of bubbling errors/exceptions must be omit?

• No need to update bubbled @throws on changes in every calling function/method
• In some cases impossible to specify all errors/exceptions thrown in called  function/method (for example, builder/factory methods)

Documentation tools must combine current PhpDoc and PhpDoc's of called functions/methods to generate complete list of @throws tags.