We're `watchtower:latest-dev` image for the `--schedule` support. This
was only available in the `latest-dev` version of Watchtower.
Now, this feature is available in the `latest` version of Watchtower, so
we should be fine switching back to `latest`.
More importantly, the `latest-dev` version of Watchtower, doesn't have
ARM images built. It only has AMD images built today. So this watchtower
service fails to start on ARM architectures. This PR fixes that.
- Add sub-directory for user to put custom certificate to use inside container
- Add flow to check existing custom certificate & process to use it
- Add section Custom Certificate in README.md
Added additional details about how to use the fat container, and how to manage / maintain it.
Also includes some refactorings that shouldn't affect the functionality significantly.
