Add kubeflow pipeline example to docs

[ukclivecox]

What this PR does / why we need it:
Adds kubeflow pipeline example to docs

Which issue(s) this PR fixes:

Fixes #

Special notes for your reviewer:

Does this PR introduce a user-facing change?:

Kubeflow pipelines end-to-end example

[seldondev]

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[seldondev]

Wed Aug 12 16:56:28 UTC 2020
The logs for [lint] [2] will show after the pipeline context has finished.
https://github.com/SeldonIO/seldon-core/blob/gh-pages/jenkins-x/logs/SeldonIO/seldon-core/PR-2265/2.log

impatient try
jx get build logs SeldonIO/seldon-core/PR-2265 --build=2

[seldondev]

Wed Aug 12 16:56:28 UTC 2020
The logs for [pr-build] [1] will show after the pipeline context has finished.
https://github.com/SeldonIO/seldon-core/blob/gh-pages/jenkins-x/logs/SeldonIO/seldon-core/PR-2265/1.log

impatient try
jx get build logs SeldonIO/seldon-core/PR-2265 --build=1