docs: add plugin setup guide

plugin/lib/commonlibf4/include/RE/A/ACTOR_VISIBILITY_MASK.h

@@ -0,0 +1,12 @@
+#pragma once
+
+namespace RE
+{
+	enum class ACTOR_VISIBILITY_MASK : std::uint32_t
+	{
+		kFrustrum = 1 << 0,
+		kOcclusion = 1 << 1,
+		kFaded = 1 << 2,
+		kAll = kFrustrum | kOcclusion | kFaded,
+	};
+}