Add conscious language module to all MTA docs

Jaromir Hradilek sent the following email to CCS:

Thank you very much to everyone who has been working on addressing problematic language in our documentation. For consistency among our documentation and to make sure our customers are aware of all this effort, we would like to ask all of you to work with your DPMs on adding the following statement at the beginning of all titles for the currently supported releases, no matter if that particular document contains problematic words or has already been updated:

"Red Hat is committed to replacing problematic language in our code, documentation, and web properties. We are beginning with these four terms: master, slave, blacklist, and whitelist. Because of the enormity of this endeavor, these changes will be implemented gradually over several upcoming releases. For more details, see our CTO Chris Wright’s message."

You can see this statement published in the RHEL documentation. To make this change in your documentation, you can download and use the following AsciiDoc module:

https://gitlab.cee.redhat.com/red-hat-enterprise-linux-documentation/rhel-8-docs/-/raw/master/enterprise/common-content/making-open-source-more-inclusive.adoc