Change page path creation to use filenames instead of titles

[marcus-grant]

Using titles as a way to create page paths is confusing. Instead change it to use filenames somehow. This query I'm not sure of but it should exist. Find it and change all of the notes paths to use it instead.

[marcus-grant]

Closing because now pages are created with paths related to slug, base-url.com/notes/${slug}. The slug is determined using gatsby-source-fileystems createFilePath function, now without trailing slashes in the slug from a change in onCreateNode in gatsby-node.

Titles which used to determined paths, is now just determined through the root h1 tag from remark. If none exists a fallback title of untitled is given.

createPage now passes along a note page with param path which is templated with notes${slug} to give pages query results for slug paths.

The tags.tsx page template now uses the appropriate slug query and path template to create links to grouped tag pages. And again, titles are only determined by heading with untitled being the title when none exists.

Handled in commit 56b195a