Update Citation, increment version

[PhilippBach]

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Description

• Increment version
• Update citation, include Journal of Statistical Software reference
• Rename format.perc ➡️ format_perc
• Fix http and broken URLs

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PR Checklist

Please fill out this PR checklist (see our contributing guidelines for details).

• The title of the pull request summarizes the changes made.
• The PR contains a detailed description of all changes and additions.
• References to related issues or PRs are added.
• The code passes R CMD check and all (unit) tests (see our contributing guidelines for details).
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