Update Go module path from github.com/kovetskiy/mark to
github.com/kovetskiy/mark/v16 across all packages and imports,
following Go module versioning conventions for major versions >= 2.
Also update README installation instructions and version string.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
ParseTitle returned lang[start:] without trimming, so inputs like
'python title My Title' returned ' My Title' with leading spaces.
The extra whitespace propagated into the rendered Confluence title
element. Add strings.TrimSpace to remove leading/trailing whitespace.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
