Function integrate_section_blocks 

pub fn integrate_section_blocks(
    doc: &mut Document,
    target_section: &BlockId,
    source_doc: &Document,
    base_heading_level: Option<usize>,
) -> Result<Vec<BlockId>>

Integrate blocks from a source document into a target section.

This takes all non-root blocks from the source document and adds them as children of the target section, preserving their relative hierarchy.

Arguments

• doc - The target document to modify
• target_section - The section to add blocks to
• source_doc - The source document containing blocks to integrate
• base_heading_level - Optional base level for heading adjustment

Returns

• Ok(Vec<BlockId>) - List of added block IDs
• Err(Error) - If the target section doesn’t exist