Description

Doc updates related to activity from these interactions:

• Add support for extracting certs from Caddy v2 data #3485 (Caddy file revisions and warning)
• bug report: docs for certificate over caddy with json might be wrong or dont work with latest caddy #3931 (comment) (Removal of Caddy JSON)
• question: Why does my mail client show a certificate for an FQDN I do not know? #3955 (comment) (Cert troubleshooting gotcha)

The diff generated isn't too helpful, especially with the removal of v2 from Caddy and Traefik headers 😅 (both have had v2 variants out long enough that this is redundant information now). Revised the content a bit, notably for Traefik removing internal details on precedence, SSL_DOMAIN and DOMAINNAME are not ENV the user should be setting.

Type of change

• Improvement (non-breaking change that does improve existing functionality)

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation (README.md or the documentation under docs/)
• New and existing unit tests pass locally with my changes
• I have added information about changes made in this PR to CHANGELOG.md