Extract ocrd manager specific configuration

[SvenMarcus]

Currently there is configuration for the communication with the OCRD manager in startup.sh, even though this repository is exclusively about providing a Kitodo Production container.
This makes for poor separation of concerns as one has to edit the content of submodules in kitodo_production_ocrd when communication details between the manager and Kitodo change and then update the main git repository accordingly.
OCRD manager specific configuration (ssh keys and so on) should therefore be extracted from this repository into kitodo_production_ocrd.

[markusweigelt]

Move the OCR-D Manager specific configuration to the ocrd_kitodo with pr slub/ocrd_kitodo#69