Data science and ml assets

[vatudorache]

data-science-and-ml content update:

• created subsection and markdown for oracle-machine-learning
• created subsection and markdown for oracle-graph-for-data-science

[github-actions]

CLA Assistant Lite bot All contributors have signed the CLA ✍️ ✅

[github-actions]

⚠️ WARNING: Missing Copyright Notice(s)
It's a good idea to have copyright notices at the top of each file. It looks like at least one file was missing this (though it might be further down in the file - this might be a false-positive).

Details:
⚠️ - :

[vatudorache]

I have read the CLA Document and I hereby sign the CLA