Update PQK tutorial to conform to new template

[MeltemTolunay]

No description provided.

[qiskit-bot]

Thanks for contributing to Qiskit documentation!

Before your PR can be merged, it will first need to pass continuous integration tests and be reviewed. Sometimes the review process can be slow, so please be patient. Thanks! 🙌

One or more of the following people are relevant to this code:

• @MeltemTolunay
• @nathanearnestnoble

[review-notebook-app]

Check out this pull request on 

See visual diffs & provide feedback on Jupyter Notebooks.

---

Powered by ReviewNB

[nathanearnestnoble]

Comment 1:
we do not seems to follow template of a small scale simulator example followed by larger hardware demonstration. For this particular tutorial, I think the point of it is improved scalaibility compared to the original kernel method. In that regard, my suggested update would be:

1. reference the quantum kernel tutorial and associated difficulty of scaling (large weight observable)
2. Include 'small scale simulator example' section and either fill it out or state 'we skip this section as the purpose of this tutorial is to demonstrate how a quantum kernel can scale' (Id probably pick the second)

Comment 2:
I would personally suggest pulling the step 3/4 explanatory text into the background section, as it helps make it more clear why scaling works

Comment 3:
I think the sentence This tutorial also assumes general familiarity with QML methods. For further exploration of QML, refer to the [Quantum machine learning](https://github.com/Qiskit/documentation/blob/d82972aee109f8a42d897f345139020b8dd8daf8/docs/tutorials/learning/courses/quantum-machine-learning) course in IBM Quantum Learning. is a bit redundant, given prereq section.