Custom IntelliSense with Monaco Editor

Cloned from monaco-editor-samples repository.

Uses simple-editor example as a start to create custom completion item provider for the XML.

Running `monaco-editor-samples`

git clone https://github.com/Microsoft/monaco-editor-samples.git
cd monaco-editor-samples
npm install .
npm run simpleserver

Go to localhost:8888 and go to simple-editor example.

MIT