SPEC: requirements and reasons only, reference material in docs/

docs/settings.md is now the one settings reference; the spec keeps the
conventions, the off list and each group's requirements and reasons, and
links to it for the per-setting entries. The endpoint list, the ban
notes, the state file contents, the rule file format and the alert
object likewise live in docs/ and are linked from the spec. The package
list from the README's Design section joins "Architecture". The nine
docs files are byte-identical to those on the README branch. Package
comments that named "Alert webhook schema", "Request log" and "Metrics
endpoint" for their field lists now name the docs files.

Model: fable-5-1

internal/remotelog/remotelog.go

@@ -1,8 +1,9 @@
 // Package remotelog sends the lines smallwebwaf writes on stdout to the
 // remote log endpoint, SWWAF_LOG_REMOTE_URL, as the "Request log" section
-// of SPEC.md describes: each line as the message of an RFC 5424 syslog
-// record, over UDP, TCP or TLS. Lines wait in a bounded buffer, so a slow
-// or unreachable endpoint never holds up a request or stdout.
+// of SPEC.md requires and "Sending the log to a syslog server" in
+// docs/request-log.md describes: each line as the message of an RFC 5424
+// syslog record, over UDP, TCP or TLS. Lines wait in a bounded buffer, so
+// a slow or unreachable endpoint never holds up a request or stdout.
 package remotelog
 
 import (