[KED-931] Option to include visualized pipelines in the generated document

[lorenabalan]

Originally raised here: kedro-org/kedro#56 by @Minyus
I've updated the title with our internal ticket number to keep track of this more easily. :)

Description

An option to include the image of visualized pipelines in the Sphinx document generated by kedro build-docs command

Context

kedro-viz offers kedro viz command that can generate interactive visualized pipelines.

This visualization is very useful to explain to the stakeholders and it is even nicer to automate the manual operation to run kedro viz command, access the URL, take a screenshot, and paste it in the document.

![image](https://user-images.githubusercontent.com/33908456/61184262-542f8000-a67e-11e9-872e-3fa40e31b81c.png)

Possible Implementation

Programmatically communicate with the kedro_viz.server.

Possible Alternatives

Use a graph visualization tool such as graphviz.

[WaylonWalker]

It should be completely possible to statically render the pipeline visualization into its own page (i.e. /viz ) then it could be iframed into any page.

[nchelaru]

This is a great idea! Any updates on this?

[yetudada]

Hi @nchelaru! We're going to look at this story in the context of a larger refactor of Kedro-Viz to make it more modular. Modularity of the flowchart component will make this easier to achieve. @limdauto can explain more 😄

[ultraxav]

Hi everyone! I currently use Kedro + viz + mlflow

What I did, is I added pipeline.json to my catalog, nodes, pipeline then I run:

kedro viz --save-file ./data/08_reporting/pipeline.json; kedro run --pipeline data_science (as an example)

This way kedro loads it and then mlflow registers it as an artifact