Feature/remark rehype

[eheimbuch]

Proposed changes

Make remark compatible with rehype plugins so we can sanitize the content with rehype-sanitize-plugin.

Your checklist for this pull request

• PR is well described and the description can be used as commit message on squash
• Related issues linked to PR if existing and labels set
• Target branch is not master (in most cases develop should bet the target of choice)
• Code does not conflict with target branch
• New code is covered with unit tests
• Changelog entry file created in gradle/changelog
• Definition of Done's fulfilled: DoD // UI DoD
• Documentation updated (only necessary for new features or changed behaviour)

Checklist for branch merge request (not required for forks)

• Branch is green/blue on Jenkins
• Quality Gate passed on SonarQube

[eheimbuch]

In general most stuff seems to be working like expected. Good job!

I couldn't manage to test the issuetracker links in markdown. How did you test it?

[eheimbuch]

When i want to use anchor links for headers with some special characters (e.g. Compl_icated_H€aDer) the anchor doesn't work properly.

[sonarcloud]

Kudos, SonarCloud Quality Gate passed!

0 Bugs
0 Vulnerabilities
0 Security Hotspots
1 Code Smell

73.0% Coverage
0.0% Duplication