Update module readme files to reflect Iris environment variables

With Iris release there are a number of new/revised environment variables for DI modules.
Update module readme files to reflect new environment settings, for example

There are several properties that should be set for modules that interact with Kafka: KAFKA_HOST, KAFKA_PORT, OKAPI_URL, ENV(unique env ID).
List of modules, for which mentioned parameters should be set:
mod-data-import
mod-source-record-manager
mod-source-record-storage
mod-inventory
mod-invoice

As noted in setup - https://wiki.folio.org/pages/viewpage.action?spaceKey=FOLIJET&title=Checklist+for+Data-Import+application+setup+on+a+new+environment%3A+Iris

Per Kate, won't take much time and is not large, and doesn't require a release