Change CHANGELOG.md template

[nikajukic]

Please use the latest version of Infinum's default changelog template and rename it to CHANGELOG.md:

Changelog

v1.0.0 (YYYY-MM-DD)

Full Changelog

Enhancements

• Added something #52

Bugfixes

• Fixed something #52

Breaking changes / Deprecations

• Changed something #52

[JureCindro]

I'm a bit confused how this can be used as the changelog contains the link to the tag/release that should already contain the updated changelog?

So the process of releasing a new version is:

1. update the changelog & the version
2. commit & push
3. run bundle exec rake release

So the tag that should be referenced in step 1 is only created in step 3.