docs: standardize page-style image captions

docs: describe contextual image captions

docs: document fast deploy mode

docs: note heading emoji cleanup

docs: refine heading and flow dedupe rules

docs: expand readability and visual hierarchy rules

docs: add readability and per-article flowchart requirements

docs: add emoji/readability/image-numbering rules

docs: improve skill readability and usage flow

feat: add DingTalk docs to HTML skill