doc: updated the tutorial pages and added more technical accuracy

[Olamideod]

#1498

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
see 45 files with indirect coverage changes

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[codspeed-hq]

Merging this PR will degrade performance by 41.82%

❌ 1 regressed benchmark
✅ 3 untouched benchmarks

⚠️ Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Benchmark	BASE	HEAD	Efficiency
❌	test_into_backend_cache	232.8 ms	400.2 ms	-41.82%

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_{Comparing Olamideod:docs/tutorial-pages (b0f8ce9) with main (9259aac)}

[letsql]

Docs preview: https://pr-1499-4875e68f6b4b5bdfddced7f9988169699c2449ab--letsql-docs.netlify.app

[mesejo]

Why do we have a file called cache_expressions_results.qmd and another one called cache_expressions_results_tutorial.qmd?

[Olamideod]

I've removed the unused file, it will be updated in the next commit.

[mesejo]

This file is very similar to compare_model_performance.qmd; the metadata (title, description, icon, headline) is exactly equal. Do you think we should delete it?

[Olamideod]

I have removed the duplicated file content.

[mesejo]

This should be rewritten to highlight what Xorq brings to the table: you can run scikit-learn ops directly on data from databases.

[letsql]

Docs preview: https://pr-1499-54410294228b3112f88737e86e679a042c0c68de--letsql-docs.netlify.app

[letsql]

Docs preview: https://pr-1499-32bdf872bd10dccfe14bfc516f01d13e66094dbe--letsql-docs.netlify.app

[letsql]

Docs preview: https://pr-1499-b0f8ce9a2fb9c247a0481e8baa8b9004d7597a94--letsql-docs.netlify.app