chore: import upstream snapshot with attribution

tests/fixtures/sample.luau

@@ -0,0 +1,35 @@
+-- Luau sample (Roblox): typed Lua superset.
+-- tree-sitter-lua doesn't parse the type annotations, but extracts
+-- function declarations and call edges fine.
+
+local Server = {}
+Server.__index = Server
+
+type ServerConfig = {
+	port: number,
+	name: string?,
+}
+
+function Server.new(config: ServerConfig): Server
+	local self = setmetatable({}, Server)
+	self.port = config.port
+	self.name = config.name or "default"
+	return self
+end
+
+function Server:start(): ()
+	print(string.format("listening on :%d", self.port))
+end
+
+function Server:stop(): ()
+	print("stopped")
+end
+
+local function main()
+	local s = Server.new({ port = 8080 })
+	s:start()
+end
+
+main()
+
+return Server