Remove legacy blog content from QMCPy docs (#587)

[sou-cheng-choi]

• Remove blogs from QMCPy docs

• Remove resume and iteration log demos

• Address remaining blog migration feedback

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Summary

• Issue:
• Algorithmic or API impact:
• Commands run:

AI Assistance

• No substantive AI assistance was used for this PR.
• AI assistance substantively affected this PR, and I describe that use below.

AI tools and affected areas:

• Independent verification performed.

Checklist

• I linked the relevant issue or explained why none was needed.
• I added or updated tests, docs, notebooks, or explained why they were not needed.
• I verified any equations, citations, benchmarks, numerical claims, or external references changed in this PR.
• I reviewed AI-assisted content for licensing, provenance, attribution, confidentiality, and security concerns.
• I described any CI, dependency, notebook runtime, or generated artifact changes if applicable.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 88.63%. Comparing base (8909780) to head (3cde6ba).
⚠️ Report is 6 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #598      +/-   ##
==========================================
- Coverage   88.64%   88.63%   -0.02%     
==========================================
  Files         103      103              
  Lines        8456     8456              
==========================================
- Hits         7496     7495       -1     
- Misses        960      961       +1     

Flag	Coverage Δ
alltests	88.63% <ø> (-0.02%)	⬇️

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see 1 file with indirect coverage changes

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[sou-cheng-choi]

@JiangruiKang

The changes are already in develop branch and we will include them in the next QMCPy release.