refactor Regex for matching section headings - merge match for annexes and for titles into one, more DRY
refactor Regex for matching section headings - merge match for annexes and for titles into one, more DRY

MjAbuz/government-digital-strategy,gds-attic/government-digital-strategy,ministryofjustice/government-digital-strategy,MjAbuz/government-digital-strategy,ministryofjustice/government-digital-strategy,MjAbuz/government-digital-strategy,gds-attic/government-digital-strategy,MjAbuz/government-digital-strategy,ministryofjustice/moj-digital-strategy,gds-attic/government-digital-strategy,ministryofjustice/government-digital-strategy,ministryofjustice/moj-digital-strategy,ministryofjustice/moj-digital-strategy