v2 Enable local development (#52)

- Create local dev environment
- Add gas-client and google-apps-script-webpack-dev-server packages for development
- Add dev/ wrapper app
- Update webpack config to support development environment
- Redesigned READMEs
- Support typescript
- Update npm scripts
- Organize and update .gitignore file
- Add .vscode settings for clasp files
- Remove tracking for files in dist/

dev/.babelrc

@@ -0,0 +1,9 @@
+{
+  "presets": [
+  	"@babel/react"
+  ],
+  "plugins": [
+  	"@babel/plugin-proposal-object-rest-spread",
+  	"@babel/plugin-proposal-class-properties"
+  ]
+}