add new AsciiDocDITA rules

[jldohmann]

this PR adds a new AsciiDocDITA rule set to the list of packages. this package attempts to find any AsciiDoc files that will not cleanly transform into DITA-compatible format so that writers can manually update those files for DITA compliance. it checks for things like the following:

• Nested sections of content (error)
• Proper content type definitions (warning)
• Cross references to files outside of the current document (warning)
• Existence of page breaks (warning)
• Lists all conditional statements in a file (suggestion)

and more

we want to enable this for the openshift-docs prow CI so that we can be sure writers are not introducing anything new that would prevent transformation to DITA formatting as they continue to work on content