Add Typescript loader to Webpack

This will allow us to use Typescript in this project.

Bug: translateselectedtext:15
Change-Id: I98eca38e26759fb91fd6cc84a589ce94e31ad70c
diff --git a/src/options/credits.json5 b/src/options/credits.json5
index 9d3aaa4..6572988 100644
--- a/src/options/credits.json5
+++ b/src/options/credits.json5
@@ -47,6 +47,18 @@
     "license": "MIT License"
   },
   {
+    "name": "source-map-loader",
+    "url": "https://github.com/webpack-contrib/source-map-loader",
+    "author": "JS Foundation and other contributors",
+    "license": "MIT License"
+  },
+  {
+    "name": "ts-loader",
+    "url": "https://github.com/TypeStrong/ts-loader",
+    "author": "TypeStrong",
+    "license": "MIT License"
+  },
+  {
     "name": "webpack",
     "url": "https://github.com/webpack/webpack",
     "author": "JS Foundation and other contributors",