🆕 Changes in this version:
* Vector graphics: added Arc and Circle.
* Navigation: added Hyperlink methods for producing links within or outside the document.
The main demo (pdf_out_demo.adb) includes now some pie charts and hyperlink examples.
An additional demo shows graphically various steps of the k-means data clustering / unsupervised machine learning method.
* Create apdf-6.0.0.toml
* Update apdf-6.0.0.toml
Just triggering a new automated test (archive name was wrong on SF).
* Update apdf-6.0.0.toml
Added some demos as executables (for `alr run`)
Also applied the rest of transformations described in alire#227: no top-level
[genera] table, name/version keys, [[depends-on]] array instead of table.