Setup pw_web_ui with Bazel and Jasmine

Initialize the pw_web_ui package and add Bazel as a build system. Add a single example test in `src/transport/web_serial_transport_test.ts` to verify Bazel can build and run Jasmine tests.

HAS_TO_BE_LARGE=Initializing a new package. Most of this is due to yarn.lock.

Change-Id: Ie3adbdba5a91de9a5f16205be8077bafb3a1fee3
diff --git a/tsconfig.json b/tsconfig.json
new file mode 100644
index 0000000..89fde41
--- /dev/null
+++ b/tsconfig.json
@@ -0,0 +1,33 @@
+// Copyright 2020 The Pigweed Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may not
+// use this file except in compliance with the License. You may obtain a copy of
+// the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+// License for the specific language governing permissions and limitations under
+// the License.
+
+{
+  "compilerOptions": {
+    "target": "es5",
+    "downlevelIteration": true,
+    "lib": [
+      "dom",
+      "dom.iterable",
+      "esnext"
+    ],
+    "esModuleInterop": true,
+    "allowSyntheticDefaultImports": true,
+    "strict": true,
+    "forceConsistentCasingInFileNames": true,
+    "module": "esnext",
+    "moduleResolution": "node",
+    "jsx": "react",
+    "sourceMap": true,
+  },
+}