Instead of using podman commands directly in the Makefile, add
the `docsbuilder.sh` script from the [docs templates repo][1].
Rewrite the Makefile to use docsbuilder commands to perform
its functions.
Changes:
- The preview URL changes from `https://localhost:8000` to
`https://localhost:8080/`
- `build` is now a synonym for `doc`
- `serve` now runs `docsbuilder -p` which automatically
rebuilds the doc first
- `watch` is now available to start a server that
automatically rebuilds the preview on file changes
- `linkcheck` will automatically start a preview server
before running `linkchecker`
[1]: https://gitlab.com/fedora/docs/templates/fedora-docs-template
