Update inline docs

[flimmy]

i have updated some of the inline documentation.

• added "COMPOSE_FILE=" example for running with an external idp
• moved "TRAEFIK_CERTS_DIR=./certs" from textflow into its own line for external cert usage
• removed leading space from some commented vars, to be in one column with all other vars
• uncommented the following env-vars:
  • OC_CONFIG_DIR, OC_DATA_DIR
  • LDAP_CERTS_DIR, LDAP_DATA_DIR
    to make it more obvious these are important, but left them empty to fallback to default internal volumes