Update dependency markdown-it to v15

[renovate]

This PR contains the following updates:

Package	Change	Age	Confidence
markdown-it	14.3.0 → 15.0.0

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Release Notes

markdown-it/markdown-it (markdown-it)

v15.0.0

Compare Source

Added

• Exposed parser internals classes as static properties on markdownit.
• Bundled TypeScript declarations. Remove @types/markdown-it if you used it.
• Added the markdown-it/browser export with bundled ESM and UMD builds.
• Added colored CLI help on supported terminals via argparse 3.
• Added reference labels to link/image tokens, #​938.
• Added reference_definition tokens. They remain stripped by default
  for backwards compatibility, #​1055. Also adjusted the line-break heuristic
  to keep output exactly the same.

Changed

• [breaking] linkify-it => v6
  • No fuzzy links by default.
  • No auth part check by default.
  • Unicode punctuation terminates the link by default (should help with CJK).
  • See linkify-it changelog
    for other changes.
• Package root now resolves to prebuilt ESM and CJS files instead of raw
  sources. Distribution files were reorganized under dist/ and
  dist/browser/.
• Migrated to Typescript.
• entities => v8. Can be rolled back to v7 if compatibility issues happen.
• Moved validateLink, normalizeLink and normalizeLinkText from properties
  to prototype methods.
• Reworked issue templates and contribution guidelines.

Removed

• [breaking] Removed package-internal subpath exports (markdown-it/lib/* and similar).
  Use the static classes exposed on markdownit instead.
• [breaking] Removed obsolete StateBlock#ddIndent, #​1139. Update
  markdown-it-deflist to keep it working.

Fixed

• Preserve a literal backslash before a terminating space in link destinations,
  matching CommonMark 6.3, #​1188.
• Recognize lowercase declarations as HTML blocks, matching CommonMark 4.6,
  #​1189.
• Require semicolons for named entities in all decoding paths, completing the
  fix for #​1096.
• Enhanced the text_join rule to process image alt text.
• Include inline code content in image alt text, #​1142.

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