webplayer: show list of speakers/contributors

[madmas]

use podlove player feature to show the speakers present in a episode

look for contributors in https://docs.podlove.org/podlove-web-player/v5/configuration/#episode

Markdown files containing episodes meta data have this block available:

  l33tname: false
  madmas: true
  ingo: true
  felix: true

would be nice to use our details from a markdown file to show links to our profiles...and maybe then use those details for our "about us" page