Add QuiddityML to Courses

[Shaier]

Summary

Adds QuiddityML to Learn → Courses as one new entry.

Scope and problem

Pillar: AI foundations. Developers who finish a course forget most of it within weeks and have nothing hands-on to hold it. QuiddityML pairs each concept (activations, backprop, optimizers, attention, embeddings) with short lessons, hands-on coding exercises drawn from 11 types (fill in the blank, spot the bug, order the code, write it from scratch), and spaced-repetition review scheduled by what the learner got wrong.

Evidence and distinction

• Primary source: https://quiddityml.com/ (curriculum: Python, PyTorch, math for ML, ML foundations, NLP, computer vision).
• Distinction: the current Courses entries are lecture or notebook courses (Fast.ai, Karpathy, MIT 6.S191). None grades exercises per concept or schedules review by spaced repetition. No adoption claims made.

Maintenance and limitations

Actively maintained: new lessons and posts weekly, latest release September 2026. Free tier covers the first units of each track; a paid tier unlocks the rest.

Affiliation

I am the author and owner.

Test plan

Ran python3 -m unittest discover -s tests -v (12 tests, OK) and scripts/validate_readme.py README.md --base upstream/master with and without --check-links (78 resources, 0 errors, 0 warnings).

Risks

None beyond a single added line.

Related issue

None.

[greptile-apps]

Confidence Score: 5/5

The PR appears safe to merge; the prior campaign-tracking concern was resolved by switching to the canonical URL.

Summary

This PR adds QuiddityML to the Learn → Courses catalog as a direct HTTPS resource with a concise description of its lessons, coding exercises, spaced repetition, and curriculum coverage.

• Places the resource within the AI foundations pillar.
• Uses the catalog’s standard entry format.
• The change since the previous review replaces the campaign-tracked URL with the canonical resource URL.

_{Reviews (2) · Last reviewed commit: "Use canonical URL"}