Add Spark Example Notebook + install with [all]

[winfried-ripken]

Description

Add tutorial how to use preprocessing with spark (8) + reference it in docu.

Small changes:

• readme.md with instal [all] option
• remove colab buttons

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update
• Refactoring including code style reformatting
• Other (please describe):

Checklist:

• I have read the [contributing guideline doc] () (external only)
• I have signed the [CLA] () (external only)
• Lint and unit tests pass locally with my changes
• I have kept the PR small so that it can be easily reviewed
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• All dependency changes have been reflected in the pip requirement files.

[TiansuYu]

One thing needs to be changed. Others LGTM

[AlpAribal]

I don't think the beta testers will be able to run this nb without additional help. Other changes lgtm.