DOC: Standardize docstrings in quadsums.jl to follow style guide

[Copilot]

• Analyze quadsums.jl docstrings against style guide
• Update var_quadratic_sum docstring formatting
  • Added four-space indented function signature
  • Changed section headers from ##### to #
  • Added blank lines after section headers
  • Removed spaces before colons in parameter descriptions
  • Ensured all descriptions end with periods
  • Fixed typo: "condtion" → "condition"
  • Broke long lines at 92 characters or less
• Update m_quadratic_sum docstring formatting
  • Added four-space indented function signature
  • Changed section headers from ##### to #
  • Added blank lines after section headers
  • Removed spaces before colons in parameter descriptions
  • Ensured all descriptions end with periods
  • Removed extra spaces in text
  • Broke long lines at 92 characters or less
• Test documentation build - passed without errors
• Run validation scenarios - all tests passed
• Final review and completion

Original prompt

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This section details on the original issue you should resolve

<issue_title>DOC: Update docstrings in quadsums.jl</issue_title>
<issue_description>Follow the instruction in .github/copilot-instructions.md.

Scope: Only edit docstrings in quadsums.jl</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes DOC: Update docstrings in quadsums.jl #350

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[Haruki1225]

@copilot
Some docstring lines are too long. Break lines (of docstring) at 92 characters (or less).

[Copilot]

@copilot
Some docstring lines are too long. Break lines (of docstring) at 92 characters (or less).

Fixed in commit 62cd559. All docstring lines now break at 92 characters or less.