Page title is set incorrectly.

[majkrzak]

When page title is omitted in the front matter it is incorrectly defaulted to the first text of the content.

[majkrzak]

This can be solved by disabling [jekyll-titles-from-headings](https://github.com/benbalter/jekyll-titles-from-headings) plugin, which for some awkward reason is always enabled and can not be disabled.

GitHub Pages uses plugins that are enabled by default and cannot be disabled:
https://docs.github.com/en/pages/setting-up-a-github-pages-site-with-jekyll/about-github-pages-and-jekyll#plugins