ISO 9001 Documentation requirements

There may be more than one interpretation to your question. Let us assume that documentation requirements is another way of saying which are mandatory according to ISO 9001:2015 requirements?

Please check this article about mandatory documentation - List of mandatory documents required by ISO 9001:2015 - https://advisera.com/9001academy/knowledgebase/list-of-mandatory-documents-required-by-iso-90012015/ Based on that approach I say that the only one is 2-Audit reports (see in the article Results of internal audits (clause 9.2)). 

It is not mandatory to have a Quality Manual or quality procedures for example.

You can find more information about ISO 9001:2015 below:

• Free online training ISO 9001:2015 Foundations Course - https://advisera.com/training/iso-9001-foundations-course/
• Book - Managing ISO Documentation: A Plain English Guide - https://advisera.com/books/managing-iso-documentation-plain-english-guide/