How to add Number Bullet lists and Sub Number Bullet list

[loki4514]

Environment

1. node -v: [fill]
2. npm -v: [fill]
3. npm ls officegen: [fill]
4. Operating system: [fill]
5. Microsoft Office version: [fill]
6. Problem with Powerpoint, Excel or Word document: [fill]

Steps to Reproduce

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Expected Behavior

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Actual Behavior

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An example code will be the best.
The fastest (and the most fun) way to resolve the issue is to submit a pull-request yourself.