Prepare production deployment

To fulfill all requirements for a production app, the following changes need to be made before deploying the application:

• Add an "Impressum" section, using the Impressum of the Regesta Imperii project: http://www.regesta-imperii.de/impressum.html
• Add a privacy/"Datenschutz" section, using the notice of the Regesta Imperii project as a foundation: http://www.regesta-imperii.de/datenschutz.html
  • The app itself does not collect any data using cookies or any other technique. The only data is gathered via the access log of the nginx server.
• Add a modal containing the license information for the third party licenses used by the application. It should possibly located on the "Impressum" page.

Additionally, the project description could be enhanced by a short description about the RIgoesGraph project specifically.