fixed some style issues, added tooling for docs

docs/network/network_nic.md

@@ -0,0 +1,11 @@
+# network/network_nic.h
+
+## class NetworkNic — public interface
+
+### `virtual void recv_pkt(Packet &pkt, PortId ingress) override;`
+### `void attach_host(Host* host) noexcept;`
+### `void detach_host(Host* host) noexcept;`
+### `void set_status(NodeStatus s, Time new_latency = Time(0)) noexcept;`
+### `const NicTelemetry &telemetry() const noexcept { ... }`
+### `void set_port_blacklisted(PortId port, bool blacklisted) noexcept;`
+### `bool is_port_blacklisted(PortId port) const noexcept;`