[SPARK-32204][SPARK-32182][DOCS] Add a quickstart page with Binder integration in PySpark documentation
### What changes were proposed in this pull request?
This PR proposes to:
- add a notebook with a Binder integration which allows users to try PySpark in a live notebook. Please [try this here](https://mybinder.org/v2/gh/HyukjinKwon/spark/SPARK-32204?filepath=python%2Fdocs%2Fsource%2Fgetting_started%2Fquickstart.ipynb).
- reuse this notebook as a quickstart guide in PySpark documentation.
Note that Binder turns a Git repo into a collection of interactive notebooks. It works based on Docker image. Once somebody builds, other people can reuse the image against a specific commit.
Therefore, if we run Binder with the images based on released tags in Spark, virtually all users can instantly launch the Jupyter notebooks.
<br/>
I made a simple demo to make it easier to review. Please see:
- [Main page](https://hyukjin-spark.readthedocs.io/en/stable/). Note that the link ("Live Notebook") in the main page wouldn't work since this PR is not merged yet.
- [Quickstart page](https://hyukjin-spark.readthedocs.io/en/stable/getting_started/quickstart.html)
<br/>
When reviewing the notebook file itself, please give my direct feedback which I will appreciate and address.
Another way might be:
- open [here](https://mybinder.org/v2/gh/HyukjinKwon/spark/SPARK-32204?filepath=python%2Fdocs%2Fsource%2Fgetting_started%2Fquickstart.ipynb).
- edit / change / update the notebook. Please feel free to change as whatever you want. I can apply as are or slightly update more when I apply to this PR.
- download it as a `.ipynb` file:
- upload the `.ipynb` file here in a GitHub comment. Then, I will push a commit with that file with crediting correctly, of course.
- alternatively, push a commit into this PR right away if that's easier for you (if you're a committer).
References:
- https://pandas.pydata.org/pandas-docs/stable/user_guide/10min.html
- https://databricks.com/jp/blog/2020/03/31/10-minutes-from-pandas-to-koalas-on-apache-spark.html - my own blog post .. :-) and https://koalas.readthedocs.io/en/latest/getting_started/10min.html
### Why are the changes needed?
To improve PySpark's usability. The current quickstart for Python users are very friendly.
### Does this PR introduce _any_ user-facing change?
Yes, it will add a documentation page, and expose a live notebook to PySpark users.
### How was this patch tested?
Manually tested, and GitHub Actions builds will test.
Closes #29491 from HyukjinKwon/SPARK-32204.
Lead-authored-by: HyukjinKwon <gurwls223@apache.org>
Co-authored-by: Fokko Driesprong <fokko@apache.org>
Signed-off-by: HyukjinKwon <gurwls223@apache.org>
b54103016a
