The default behavior of most ACME clients is to generate a new key pair
at each renewal. While this choice is respectable and perfectly
justified in most configuration, it is also quite incompatible with the
use of HTTP Public Key Pinning (HPKP). Although HPKP is not wildly
supported and sometimes deprecated, users wishing to use it should not
be blocked.
https://tools.ietf.org/html/rfc7469https://en.wikipedia.org/wiki/HTTP_Public_Key_Pinning
Both markdown and CommonMark support only 2 level of heading underline.
A third level using the `~` character is only supported as an extension
in some implementations. While GitHub and most software do not support
it, it is a better choice to switch to ATX headings.
https://daringfireball.net/projects/markdown/syntaxhttps://spec.commonmark.org/