docs: BGP network map + CHIMERA architecture plan

Ground truth read from CiscoConfigs: 3 RR clusters (HQ 64572/6.7.6.7,
NEKOS 64600/172.19.67.0, VyOS transit 64580/67.67.21.37), RR-PEERS+CLIENTS
peer-group scheme, config quirks (nested AF stanzas, NYATER 4th RR,
commented-out RCC on VyOS transit RRs, shared .186 router-id).

Architecture: declarative YAML inventory, normalized bgpd parser, vtysh
plan/diff/apply engine with canary rollout and rollback, CLI verbs,
docker FRR e2e lab, roadmap M0-M5.

README.md

@@ -2,4 +2,18 @@
 
 ## BGP Route Reflector synchronizer
 
-![Unrelated pic](https://data.shupogaki.org/assets/1/HOQhOGVaoAA_2t3.jpeg)
+![Unrelated pic](https://data.shupogaki.org/assets/1/HOQhOGVaoAA_2t3.jpeg)
+
+## Docs
+
+- [docs/BGP-NETWORK.md](docs/BGP-NETWORK.md) — the real BGP network: AS plan,
+  RR clusters (HQ AS 64572 cluster-id 6.7.6.7, NEKOS AS 64600 cluster-id
+  172.19.67.0, transit AS 64580), peer-groups (RR-PEERS / CLIENTS), addressing,
+  and every config quirk CHIMERA must handle.
+- [docs/ARCHITECTURE.md](docs/ARCHITECTURE.md) — codebase layout, data model,
+  vtysh plan/apply engine, CLI verbs, test lab, roadmap.
+
+Source configs orchestrated by CHIMERA:
+`CiscoConfigs/MP-BGP_EVPN_VXLAN_V2/HQ/FRR/RouteReflectorLXC/` (HQ FRR RRs on
+Debian LXC), `.../NEKOS/FRR/RR/` + `NEKOS/REIMU` (NEKOS RRs), VyOS transit in
+`CiscoConfigs/VyOS/HQ/`. FRR docs: https://docs.frrouting.org/en/latest/ .