Normalize separator characters in adoc file names

Following the guidance in https://github.com/redhat-documentation/modular-docs/issues/111, some file names were implemented with underscores after the information typing prefix. Not all were updated, so file names are inconsistent.

There is now discussion about which convention we will use.

When we determine the final convention, we need to normalize file names that use the information typing prefix so all consistently follow the convention.