Document multi-page views

[tjerman]

This ticket will probably require you to change other parts of the docs so let's tackle it together.

The documentation should go here

• [x] Document what the feature is, what it enables
• [x] Document how to configure and use

Original issue https://github.com/cortezaproject/corteza/issues/479 Might also include https://github.com/cortezaproject/corteza/issues/480

[tjerman]

V1 version - https://www.github.com/cortezaproject/corteza-docs/commit/80bb4a28; will revisit and see how it can be improved