Rework the README after the second review

The nine findings: the heap figure keeps the old README's meaning; the
Makefile sentence names the three targets that call no script; the five
fields /api/v1/stats adds are a list; the test comment names README
"JSON API"; the X-Forwarded-For readers are a list, with short sentences
after it; the AS page's peers are the ASes next to it in AS paths; CIDR
ranges and the default route are explained; handle and description are
field names; the TODO entry is one sentence.

The sweep of every sentence defined feed, carry, IANA, multicast,
handler, streamer, reverse proxy and goroutine at first use, split the
list of parts, and named the 404 of an unknown page path.

Model: fable-5-1

TODO.md

@@ -35,12 +35,8 @@ tested.
 
 # Completed Steps
 
-- 2026-11-02: `README.md` rewritten from scratch, sentence by sentence, against
-  the rules of https://git.eeqj.de/sneak/routewatch/issues/157. It leads with
-  what RouteWatch is and how to run it, then the pages and the API, then the
-  settings, memory and upaas, and ends with the design and development. Every
-  statement was checked against the code (part of
-  https://git.eeqj.de/sneak/routewatch/issues/157)
+- 2026-11-02: `README.md` rewritten from scratch, sentence by sentence, and
+  checked against the code (part of #157)
 - 2026-10-27: the tests of `internal/routewatch` no longer fail on a loaded
   host. Five of them gave `HandleMessage` two seconds to apply a full prefix
   batch, which under the race detector can take longer. A test now waits up to