SPEC: false statements fixed, repeats removed, dropped requirements restored

The bounds sentence, the blocklist URL sentence, the deny list sentence,
the limit action's scope and the observe mode sentence now say what the
code does. Each of the twenty-one requirements the fourth review found
twice is stated once, with a link from the other place. The request id
header, redirect_uri's case, change 4's reason and the live archive's
InRelease files are back. The biased thresholds are defined where they
are introduced. The docs files apply the fifth README review's findings
and stay identical to the README branch.

Model: fable-5-1

docs/request-log.md

@@ -12,9 +12,13 @@ sent to a syslog server. A field that does not apply to a request is left out.
 
 ## Every line
 
-Every line has `type` (`request`; the process's own messages have `process`),
-the standard web log fields, `request_id`, `peer_ip`, `client_group`, `asn`,
-`as_name`, `country`, `action` and `duration_total`.
+Every line has:
+
+- `type`: `request` (the process's own messages have `process`);
+- the standard web log fields;
+- `request_id`, `peer_ip` and `client_group`;
+- `asn`, `as_name` and `country`;
+- `action` and `duration_total`.
 
 ## Standard web log fields
 
@@ -28,7 +32,7 @@ the standard web log fields, `request_id`, `peer_ip`, `client_group`, `asn`,
 ## Request detail
 
 - `request_id`: the `X-Request-ID` a trusted proxy sent, or a new random one of
-  26 letters and digits. It goes to the app in `X-Request-ID`.
+  26 letters and digits.
 - `peer_ip`: the TCP peer, normally traefik.
 - `forwarded_for`: the `X-Forwarded-For` header as received.
 - `client_group`: the client as rate limiting counts it, an IPv4 address as a
@@ -73,15 +77,22 @@ the standard web log fields, `request_id`, `peer_ip`, `client_group`, `asn`,
   rate limits and the setting that lowered it, when one did. `bytes_percent` and
   `bytes_percent_setting` do the same for the byte limits.
 - `counts`: the client's totals as rate limiting counts them, this request
-  included. It is left out when rate limiting did not count the request. A count
-  can have a fraction, since each window is counted in two buckets with the
-  earlier one weighted:
+  included. It is left out when rate limiting did not count the request. It
+  holds:
     - `minute`, `hour` and `day`: requests;
     - `minute_bytes`, `hour_bytes` and `day_bytes`: bytes.
-- `limit_hit`: the limit broken: `minute`, `hour` or `day` for a rate limit;
-  `minute_bytes`, `hour_bytes` or `day_bytes` for a byte limit; or
-  `error_burst`. A request whose bytes broke a limit was passed on whole, so its
-  `action` stays `forward`.
+
+    A count can have a fraction (see "Counting method" in
+    [`SPEC.md`](../SPEC.md)).
+
+- `limit_hit`: the limit broken:
+    - `minute`, `hour` or `day` for a rate limit;
+    - `minute_bytes`, `hour_bytes` or `day_bytes` for a byte limit;
+    - `error_burst`.
+
+    A request whose bytes broke a limit was passed on whole, so its `action`
+    stays `forward`.
+
 - `rule_ids`: the rule file rules that matched, in order, up to the one that
   refused.
 - `waf_score` and `waf_rule_ids`: the Core Rule Set's score and the rules that
@@ -91,7 +102,7 @@ the standard web log fields, `request_id`, `peer_ip`, `client_group`, `asn`,
     - the CrowdSec decision list's URL;
     - DNS blocklist zones;
     - `abuseipdb`.
-- `offence`: the kind of offence recorded, when one was.
+- `offence`: `limit`, for a request that broke a limit.
 - `ban_expires`: when the client's ban ends, for a request that made one or was
   refused under one: a time, or `permanent`.