Make it clearer what the on-going value is for the Heroku landing page

[Comment from Josh](https://gruntwork-io.slack.com/archives/C0275GS2FKM/p1627944021089500?thread_ts=1627689536.033800&cid=C0275GS2FKM):

> Separately, it occurs to me that we’re charging a recurring fee for a solution focused on a one-time migration. Perhaps we need to more clearly state what happens ongoing here.

We should probably flush out more that we provide commercial support + maintenance for all of the infrastructure code, and _perhaps_ a central UI to see all your migrated apps, their logs, etc.