fixed some style issues, added tooling for docs

docs/hosts/policies.md

@@ -0,0 +1,20 @@
+# hosts/policies.h
+
+## class PubBasePolicy — public interface
+
+### `virtual ~PubBasePolicy() = default;`
+
+## class PubRRPolicy — public interface
+
+### `: _ranges(std::move(ranges)) { ... }`
+### `validate_and_build();`
+### `PacketGroups select_multicast_groups(PacketGroups update_groups_mask) override { ... }`
+### `for (auto const& r : _ranges) { ... }`
+
+## class SubBasePolicy — public interface
+
+### `virtual ~SubBasePolicy() = default;`
+
+## class SubDummyPolicy — public interface
+
+### `~SubDummyPolicy() override = default;`