Apply SPDX copyright and license headers in compliance with REUSE
Inspired by the work on KDE Frameworks 6 .
Some of the license texts under LICENSES/ are our original copies
(sourced from whoever published the license) instead of the unformatted
version downloaded by REUSE.
Switch to JSON front matter
This makes the front matter compatible with Pandoc (as YAML is defined
as a superset of JSON).
Adjust TOC so it is more accessible (I hope)
haunt: Add TOC generation
haunt: Split utility modules off haunt.scm
With the upcoming TOC generation, the file will get too big for proper