def sections(section_changes, header_style, entry_style)
      str = ""
      section_changes.each do |section_category, section_changes|
        str << section(
          section_changes,
          section_category.to_s,
          entry_style,
          header_style
        )
      end
      str
    end
def sections(section_changes, header_style, entry_style)
      str = ""
      section_changes.each do |section_category, section_changes|
        str << section(
          section_changes,
          section_category.to_s,
          entry_style,
          header_style
        )
      end
      str
    end
Format each section from #sections.

 section_changes ... changes in the format of { section_1: [changes...], section_2: [changes...]}
 header_style ... is called for styling the header of each section
 entry_style ... is called for styling each item of a section