some support for fixed number

src/commonMain/kotlin/net.sergeych.bintools/DataSink.kt

@@ -36,6 +36,10 @@ inline fun <reified T:Any>DataSink.writeNumber(value: T) {
 fun DataSink.writeI32(value: Int) {
     writeBytes(intToBytes(value))
 }
+
+fun DataSink.writeI16(value: Short) {
+    writeBytes(shortToBytes(value))
+}
 fun DataSink.writeU32(value: UInt) {
     writeBytes(uintToBytes(value))
 }