bug: incorrect parsing of indented single - in Markdown

[liftctrl]

Did you check existing issues?

• I have read all the tree-sitter docs if it relates to using the parser
• I have searched the existing issues

Tree-Sitter CLI Version, if relevant (output of tree-sitter --version)

No response

Describe the bug

The Markdown parser incorrectly parses a single indented - as a Setext-style H2 heading.

Steps To Reproduce/Bad Parse Tree

1. Start Neovim with no plugins loaded:

nvim --clean

2. Create a markdown file with the following content:

- setup
  -

3. Run :InspectTree on the first line in Neovim.

(document ; [0, 0] - [2, 0]
  (section ; [0, 0] - [2, 0]
    (list ; [0, 0] - [2, 0]
      (list_item ; [0, 0] - [2, 0]
        (list_marker_minus) ; [0, 0] - [0, 2]
        (setext_heading ; [0, 2] - [2, 0]
          heading_content: (paragraph ; [0, 2] - [1, 2]
            (inline ; [0, 2] - [0, 7]
              (inline)) ; [0, 2] - [0, 7]
            (block_continuation)) ; [1, 0] - [1, 2]
          (setext_h2_underline)))))) ; [1, 2] - [1, 3]

Expected Behavior/Parse Tree

• The first line - setup should be parsed as a list item.
• The second line with the indented - should be parsed as an empty child list item.

Repro

No response