Release shell changelog multiline comments are converted into separate comments.

[sakarias88]

In the case where a change is described in multiple lines such as the following example.

## Unreleased

### Added
- Added a seriously long line to the change log
  with a very descriptive description.

When we go into the release shell and prepare the changelogs and move it to the Firm changelog double lines are converted into separate items like in the example below.

## Firm [1.1.1]

### Added
- Added a seriously long line to the change log
- with a very descriptive description.

This is an unexpected behavior. We tracked the problem down to the keepachangelog python library only working on lines and not considering that a comment might be on several lines. https://github.com/Colin-b/keepachangelog/blob/3538c5b4beb433293352d084f4df7bcce4d02bf1/keepachangelog/_changelog.py

Suggested solutions:
1: We don't make newlines in comments.
2: Patch the keepchangelog parser, send them a pull request (https://github.com/Colin-b/keepachangelog).