add swift flatbuffers

flatbuffers/Documentation.docc/Resources/code/swift/swift_code_13.swift

@@ -0,0 +1,26 @@
+import FlatBuffers
+import Foundation
+
+func run() {
+  // create a ByteBuffer(:) from an [UInt8] or Data()
+  let buf = [] // Get your data
+  var byteBuffer = ByteBuffer(bytes: buf)
+  // Get an accessor to the root object inside the buffer.
+  let monster: Monster = try! getCheckedRoot(byteBuffer: &byteBuffer)
+  // let monster: Monster = getRoot(byteBuffer: &byteBuffer)
+
+  let hp = monster.hp
+  let mana = monster.mana
+  let name = monster.name // returns an optional string
+
+  let pos = monster.pos
+  let x = pos.x
+  let y = pos.y
+
+  // Get and check if the monster has an equipped item
+  if monster.equippedType == .weapon {
+    let _weapon = monster.equipped(type: Weapon.self)
+    let name = _weapon.name // should return "Axe"
+    let dmg = _weapon.damage // should return 5
+  }
+}