fixed some style issues, added tooling for docs

docs/hosts/publisher.md

@@ -0,0 +1,10 @@
+# hosts/publisher.h
+
+## class Publisher — public interface
+
+### `void recv_update(Bytes size, PacketGroups update_groups_mask) noexcept;`
+### `void set_status(NodeStatus s, Time new_latency = Time{}) noexcept;`
+### `virtual void recv_mgmt_msg(MgmtMsgPtr msg) noexcept override;`
+### `virtual void recv_frame(const Packet& frame) override;`
+### `uint64_t updates_in() const noexcept { ... }`
+### `uint64_t bytes_out() const noexcept { ... }`