Update config on certificate change

[Sephsekla]

We have a site using HM-ACM which sometimes requires updating the certificate and Cloudfront distribution with new domains. This PR makes a few changes to improve this workflow:

• Added documentation for some functions.
• Allow showing/hiding of the unlink buttons for both certificates and distributions. In our use case, there's not a use case for unlinking the distribution and it's a more involved process to relink it (although I'd like to add the option to relink via a button as a followup). This avoids accidental clicks that can't be easily resolved from within the dashboard.
• Add a check for whether the Cloudfront distribution is using the correct certificate, and warning the user if not.
• Display the certificate and distribution details (within an accordion) to allow for easier debugging and checking that distributions/certificates match.

I've made this PR against #15, which I'm hoping we can also get merged and into a release. I have a couple of slightly more opinionated readability improvements as well, but I'll address those in a followup so they don't block this.

[Rayhatron]

Looking good !! Just need a safety check for a fatal error that's occurring.

[Rayhatron]

LGTM and the fatal error is no longer happening.