Improve the AWS DMS documentation

Andrew Woods (awoods187) commented:

Our current AWS DMS telemetry doesn’t address a couple of challenges in using CC dedicated.

Opportunities to improve include:

* Visuals that weave dedicated into the journey (I’m imaging a split of self-hosted vs. cloud docs)
* Showing on dedicated how to add a public/secure network that can be found by AWS DMS
* How to convert the dedicated certificate to a .PEM file (the only type accepted by AWS DMS)

Jira Issue: DOC-6079