I have to build a chatbot based on my compnay data. The data is in a pdf file. I want the chatbot to be trained in such a way that it answers any query that has an answer in the document. I dont want any hardcoding in json file where i put the questions and answers myself. The chatbot should be trained to deal with any kind of question and answer from the document. It should be able to carry on conversation as well for example if it answers a question from document and any subsequent question is asked, it should be able to answer it.