Improve release process

[mnzaki]

Description

semantic-release can create a changelog and decide on the version number automatically if we just stick to properly formatted commit messages, which we can also easily do with commitizen

Furthermore it would be useful to have some way to easily see what changed in the public interface. Either some sort of utility script to diff the .d.ts files, or maybe we should actually commit the build output as well?

TODO

• Add and configure commitizen
• Add notes/docs/links to expected commit message format
• Add and configure semantic-release