Implement frontend

[kevinstadler]

current development preview: https://releven.acdh-ch-dev.oeaw.ac.at

• include fonts
• header / footer
  • fix layout
  • remove login
  • finalize links/link texts
• pages
  • home page
    • add tablet/phone layout
    • figure out background behaviour on ultra-wide screens
    • texts
  • about / faq
    • get texts
• content pages
  • implement query wrapper
  • implement snappy caching
  • implement ordering (depends on Add option to explicitely define orderable fields acdh-oeaw/rdfproxy#271)
  • implement filtering
  • people
    • implement rdfproxy endpoint
  • places
    • implement rdfproxy endpoint
  • texts
    • implement rdfproxy endpoint
  • viewpoints
    • implement rdfproxy endpoint (based on Add support for including manually defined models/queries in entrypoint acdh-oeaw/wisskas#20)
    • implement UI

[laletuver1]

The issue #49 needs to be fixed first before continuing.

[kevinstadler]

Running listing/detail endpoints allow further work on content pages -- before moving on: should locale support (i.e. /en/ /de/ as first part of the page URLs in https://releven.acdh-ch-dev.oeaw.ac.at/en/people) be removed for good?