fix(a11y): harden Mermaid validator and fix 20 pre-type accTitle/accDescr violations#1017

ashleyshaw merged 4 commits into

developlightspeedwp/.github:developfrom

fix/mermaid-validator-pre-type-attribute-guardlightspeedwp/.github:fix/mermaid-validator-pre-type-attribute-guardCopy head branch name to clipboard