I want to make a chatbot that will answer the questions based on the given document. E.g, if I have hundreds of documents and I want to get some information from it but don't know which information is on which line of the page so I have to spend some time and effort to search. I want a chatbot that will learn from those documents and give answers form that documents.
Is there any available service that can full fill my needs?
What if I want to make a model by myself what tools/libraries do I need to make it possible?
Any help will be appreciated.
The task you are searching for is called Question Answering. In this particular case, you something that is sometimes called Answer Span Selection or Reading Comprehension.
The problem is typically approached with deep learning. There is dataset called SQuAD created at Stanford University consisting of 100k questions paired with their answers highlighted in Wikipedia articles. This is what the models are typically trained on.
You can try an online demo by Allen Institute for AI to get an idea of how the state-of-the-art looks like. I believe, it should be also able to run it locally with the AllenNLP toolkit.