Prepare release v2.7.0-hifis2

• CITATION.cff
  • Version number
  • Release date
  • Check upstream version number in references
• Create release notes

Release notes

What's changed

This is version v2.7.0-hifis2 of the Helmholtz RSD. This is a minor update applying some cosmetic changes.

HIFIS specific changes

Bug fixes

• improve readability of Link ORCID button on mouseover (c47a9dd0)
• removes beta-hint on reference papers page (7a193657)