Use first heading as title

[franco-ruggeri]

Is your feature request related to a problem? Please describe.
A clear and concise description of what the problem is. Ex. I'm always frustrated when [...]

The first H1 heading is typically used as a title for markdown notes. Right now it is not possible to use it as a title in Quartz (e.g., for what is shown in the graph view).

Describe the solution you'd like
A clear and concise description of what you want to happen.

Right now, Quartz sets the title in order of priority to:

1. frontmatter title field
2. File stem (filename without .md)
3. Locale default ("Untitled")

We can add a configuration option to use the first H1 heading as the title.

Describe alternatives you've considered
A clear and concise description of any alternative solutions or features you've considered.

Additional context
Add any other context or screenshots about the feature request here.

[BravishkaSkytano]

If you're using Obsidian, you could just install a plugin like File Title Updater to sync names between title frontmatter, the first heading of the file, and/or the filename.