fix(docs): listitems with codeblocks #42367

Problem:
- `<` before a listitem (`< - foo`) is not concealed.
- Codeblock HTML has extra blank lines.
- Codeblock in a listitem ends the listitem, so HTML docs drop the rest
  of the item and its nesting. Example from `:h nvim_open_win()`:
  ```
        • border: … the double-box style can be specified as: >
          [ "╔", "═" ,"╗", "║", "╝", "═", "╚", "║" ].
    <
          If fewer than eight chars are given, they will be repeated.
        • bufpos: …

    tree-sitter-vimdoc v4.1.0:
      (block
        (line_li (prefix) (line) (codeblock (code (line)))))
      (block
        (line)                                  ; "If fewer…"
        (line_li (prefix) (line) (line)))       ; "bufpos"

    tree-sitter-vimdoc v4.2.0:
      (block
        (line_li (prefix) (line) (codeblock (code (line)))
          (line))                               ; "If fewer…"
        (line_li (prefix) (line) (line)))       ; "bufpos"
  ```

Solution:
- Bump tree-sitter-vimdoc to v4.2.0. https://github.com/neovim/tree-sitter-vimdoc/pull/174
- gen_help_html: get listitem indent from its first line
- gen_help_html: don't double codeblock newlines.
- highlight query: conceal `<` in `line_li`.
- docs: fix doc sources where a blank line was missing after listitems
  followed by non-listitem text.

0 files changed, 0 insertions, 0 deletions