adds pseudo.cortex.consider-funding.de upstream, adds snippet for easy oauth2-proxy protect, moves oauth2-proxy secrets to .env file

docker_compose_applications/oauth2-proxy/oauth2-proxy.cfg

@@ -0,0 +1,9 @@
+provider = "entra-id"
+upstreams = ["file:///dev/null"]
+http_address = "0.0.0.0:4180"
+whitelist_domains = [".consider-it.de", ".consider-funding.de"]
+cookie_secure = true
+email_domains = [ "*" ]
+scope = "openid"
+skip_provider_button = true
+set_xauthrequest = true