Add a super simple typescript example

Change-Id: I1014a889a3bb74f291a214966b32cd21e791ed7c
diff --git a/y2019/vision/server/demo.ts b/y2019/vision/server/demo.ts
new file mode 100644
index 0000000..b310758
--- /dev/null
+++ b/y2019/vision/server/demo.ts
@@ -0,0 +1,5 @@
+declare var foo: number;
+
+foo = 5;
+
+console.log("Half the number of widgets is " + (foo / 2));