nvim-treesitter/queries/markdown/highlights.scm

;; From MDeiml/tree-sitter-markdown
[
  (atx_heading)
  (setext_heading)
] @text.title

(code_fence_content) @none

[
  (indented_code_block)
  (fenced_code_block)
  (code_span)
] @text.literal


(emphasis) @text.emphasis

(strong_emphasis) @text.strong

(link_destination) @text.uri

(link_label) @text.reference

[
  (list_marker_plus)
  (list_marker_minus)
  (list_marker_star)
  (list_marker_dot)
  (list_marker_parenthesis)
] @punctuation.special

[
  (backslash_escape)
  (hard_line_break)
] @string.escape