Versionist is a small utility to automatically generate CHANGELOGs based
on a certain commit convention.
This PR adds a new `changelog` npm script that calls Versionist to
preppend a new CHANGELOG entry based on our current structure.
Dealing with links to changes between versions in GitHub is hard to
automatise with a tool like Versionist. We chose to get rid of such
links since they are a nice to have, but don't provide any meaningful
value to maintainers, since they can manually see the diffs with `git
diff`.
Signed-off-by: Juan Cruz Viotti <jviottidc@gmail.com>