Tergi 130 review documentation

Closes #22 (closed)

Closes #31 (closed)

• tackle roles (terminology administrator / manager, TerminoloGit admin)
  • architecture_en.md
  • file_formats_en.md -> propCSV
• review spelling of code system / value set / CodeSystem / ValueSet / etc.
• translate to German
  • review references to files / URLs / etc.
  • review spelling of code system / value set / etc.