Fix broken links and redirects in documentation

[Copilot]

This PR addresses the 119 redirected URLs found by the automated link checker to improve documentation performance and reliability by updating URLs to their final destinations.

Changes Made

Updated URLs across 10 lecture files to eliminate unnecessary redirects:

• FRED URLs: Updated research.stlouisfed.org/fred2/ → fred.stlouisfed.org/
• JAX repository: Updated github.com/google/jax → github.com/jax-ml/jax
• NumPy documentation: Updated docs.scipy.org/doc/numpy/ → numpy.org/doc/stable/
• JAX documentation: Updated jax.readthedocs.io → docs.jax.dev
• QuantEcon.py: Updated http://quantecon.org/quantecon-py → https://quantecon.org/quantecon-py/
• GitHub resources: Updated various GitHub URLs to current paths (help.github.com → docs.github.com, desktop.github.com → github.com/apps/desktop, etc.)
• Library documentation: Updated requests docs (master → latest), conda docs, git-scm.com (http → https)
• Service URLs: Updated Anaconda blog, nbviewer (jupyter.org → nbviewer.org), Kaggle (kernels → code)
• Python resources: Updated PSF URL, GeeksforGeeks paths, Tuts+ tutorial URLs

Validation

• ✅ All changes tested with successful Jupyter Book build
• ✅ Generated HTML contains updated URLs
• ✅ Local server validation confirms site functionality
• ✅ No content changes - only URL updates to reduce redirects

The build process completed successfully with only expected warnings about jax.quantecon.org being unreachable (normal in CI environment).

Fixes #399.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• fred.stlouisfed.org
  • Triggering command: /usr/share/miniconda/envs/quantecon/bin/python -Xfrozen_modules=off -m ipykernel_launcher -f /tmp/tmpnoy12mk_.json --HistoryManager.hist_file=:memory: (dns block)
• jax.quantecon.org
  • Triggering command: /usr/share/miniconda/envs/quantecon/bin/python /usr/share/miniconda/envs/quantecon/bin/jb build lectures --path-output ./ -n -W --keep-going (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

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[github-actions]

🚀 Deployed on https://68ad3f0992e4a2824a44269d--epic-agnesi-957267.netlify.app

[mmcky]

Closed in favour of #389