enable using H1 header as title via settings (#20)
* publishing: Pull title from H1
Allows the title to be sourced from the published document's first H1
header. The order of precedence for determining the document's title is
now:
- `title` frontmatter field
- First present H1 header
- Filename
* refactor header extracting
* enable via settings
* fix lint
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Co-authored-by: Isaac Corbrey <isaac@isaaccorbrey.com>
authored by