This adds a GitHub Action workflow to sync the labels from a YAML file
in `.github/labels.yaml`.
Some of the labels have been changed for consistency, and an `aliases`
list has been defined to ensure they're renamed properly.
In terms of colors, I am still trying to figure out what looks best.
But this should be a good start to at least kick things off.
Signed-off-by: Hidde Beydals <hidde@hhh.computer>