- markdown: new directives `:::figure assets/x.png | Подпись` and
`:::video assets/x.mp4 | Подпись` rendered as figure/figcaption and a
video player (works with HTML escaping on); sanitizer allows video/source/
track/figure with safe attributes only
- assets: video extensions (mp4/webm/ogg) allowed, separate limits — images
up to 10 MB, video up to 100 MB; correct content types
- upload limits raised: web/academic multipart 120 MB per file / 200 MB per
request, nginx client_max_body_size 200m (covers media inside ZIP imports)
- docs: new docs/06-authoring.md (markdown, images, video, assets, limits,
import semantics); import message now says "медиафайлов"
Vladislav Kopnin
396221047c