Add optional Lua scripting module, examples, and validation

examples/lua/Scripts/beacon.lua

@@ -0,0 +1,27 @@
+local motion = require("util.motion")
+
+local Beacon = faset.behavior {
+    id = "example.lua_beacon",
+    version = 1,
+    name = "Lua Beacon",
+    fields = {
+        amplitude = { name = "Height", type = "number", default = 0.3, min = 0, max = 2 },
+        frequency = { name = "Frequency", type = "number", default = 0.7, min = 0, max = 5 }
+    }
+}
+
+function Beacon:on_start()
+    self.state.origin_y = self.entity:transform().position.y
+    self.state.elapsed = 0
+end
+
+function Beacon:update(delta)
+    self.state.elapsed = self.state.elapsed + delta
+    local pose = self.entity:transform()
+    pose.position.y = self.state.origin_y
+        + motion.bob(self.state.elapsed, self.fields.frequency, self.fields.amplitude)
+    pose.rotation.z = self.state.elapsed
+    self.entity:set_transform(pose)
+end
+
+return Beacon