docs(gen_help_html.lua): fix broken pre text, and handle linewrap

Problem:

- Since #28678, pre-formatted text in the online documentation do not
  render whitespaces correctly: should be pre-like text, but shown like
  normal paragraph (see #28754).

- Code blocks with long lines should not be wrapped (e.g. see
  |dev-vimpatch-list-management|).

Solution:

- Use `white-space: pre-wrap`. Compared to `white-space: pre`, this
  option will make long lines including a very long URL wrapped.
  This properly fixes #28754 and #28678.

- Use horizontal scrollbar for the code blocks that are horizontally too
  long, instead of wrapping text. This will make the code easy to read
  while the pre-text block not interfering with the navigation bar.

0 files changed, 0 insertions, 0 deletions